RingConn Gen 2 vs Ultrahuman Ring PRO vs Circular Ring 2: rings sold without a mandatory subscription
Three iOS and Android rings whose makers state no mandatory subscription, separated by stated battery life, charging case, sensors listed and the health wording each manufacturer uses.
The decision in brief
How the options differ
All three exact US packages include a charging case and leave the size to the buyer. RingConn alone states battery life by size, Ultrahuman states the longest single figure and a case with its own battery, and Circular lists the only ECG sensor. Each states different water wording, and none states a regulatory clearance for its health features.
By CompareFoundry · Published · Editorial review · Manufacturer documentation, not hands-on testing.
The buying guide
Package and specification details
Compare battery claims and their basis
RingConn states up to 10 days for sizes 6 to 7, 11 days for 8 to 11 and 12 days for 12 to 14. Ultrahuman states about 12 days in Turbo Mode and more than 15 in Chill Mode, with no size basis. Circular states about 8 days in power mode and 4 to 5 in performance mode, also with no size basis.
Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Look at the charger in the box
RingConn ships a size-specific wireless charging case that is not sold separately. Ultrahuman ships the PRO Charger case with its own battery, USB-C and Qi charging and up to a year of data storage in Chill Mode. Circular ships a wireless charging case with a USB-C cable and does not say whether the case has a battery.
Ultrahuman lists a temperature sensor, PPG and a 6-axis IMU. Circular lists ECG, PPG, temperature and a 3-axis accelerometer. RingConn's Gen 2 page lists no sensor hardware but states continuous heart rate, blood oxygen and temperature tracking.
Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Read the paid extras and health wording
RingConn lists the subscription fee as free. Ultrahuman includes core features but sells premium PowerPlugs and an optional plan; Circular unlocks a few premium screens with coins earned by wearing the ring. Ultrahuman says Ring PRO is not a medical device, RingConn says the same on its Gen 3 page, and Circular states no clearance for its ECG or AFib wording.
RingConn states IP68 (100 m/328 ft) and Ultrahuman water resistance to 100 m. Circular states IP68 with no depth or duration, and says showers and swimming are fine.
Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Common questions
Do these rings work with iPhone?
All three makers state iOS and Android support. RingConn gives iOS 17.0 or later and Android 10.0 or later; Ultrahuman and Circular publish no minimum versions on the pages read.
Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Evidence limits
These manufacturer specifications do not establish measured performance, noise, long-term reliability or running cost. We have not independently tested these products. Check current prices, stock and operating-space instructions with the seller and manufacturer.
RingConn Gen 2 Matte Black, buyer-selected size (US)RingConn Gen 2; Matte Black; size 6 to 14 chosen by the buyer with I know my size; not the Free Sizing Kit route; no trade-in
Royal Gold, Future Silver and Rose Gold are the other finishes. Gen 2 Air and Gen 3 are different models with a charging dock or a universal case.
RingConn does not publish a part number on the page read. Price and stock are not recorded.
Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Ring PRO with PRO charging case; Aster Black; size 5 to 14 chosen by the buyer with I know my ring size; no trade-in; no Ultrahuman Max plan or UltrahumanX coverage
Raw Titanium, Bionic Gold and Space Silver are the other colors. Premium PowerPlugs, Ultrahuman Max and UltrahumanX are optional paid add-ons, not part of this package.
Ultrahuman does not publish a part number on the pages read. Price, ship-by date and stock are not recorded.
Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Circular Ring 2; Obsidian Black; US size 6 to 14 chosen by the buyer with I know my size; no replica-ring sizing kit, extra charger case, extension cable or Circular+ Guarantee
Silver, Gold and Rose Gold are the other finishes. The store ships worldwide and states HSA/FSA eligibility in the US; the shipping origin is not stated.
Circular does not publish a part number on the page read. Price, delivery and stock are not recorded.
Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Where to buy
RingConn Gen 2 Matte Black, buyer-selected size (US)
Select: RingConn Gen 2; Matte Black; size 6 to 14 chosen by the buyer with I know my size; not the Free Sizing Kit route; no trade-in
The link may open several packages. Check current price and availability with the seller. Opens in a new tab.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)
Select: Ring PRO with PRO charging case; Aster Black; size 5 to 14 chosen by the buyer with I know my ring size; no trade-in; no Ultrahuman Max plan or UltrahumanX coverage
The link may open several packages. Check current price and availability with the seller. Opens in a new tab.
Circular Ring 2 Obsidian Black, buyer-selected size (US)
Select: Circular Ring 2; Obsidian Black; US size 6 to 14 chosen by the buyer with I know my size; no replica-ring sizing kit, extra charger case, extension cable or Circular+ Guarantee
The link may open several packages. Check current price and availability with the seller. Opens in a new tab.
Sizes and sizing kit
The ring sizes the manufacturer lists for the US and how its sizing kit is offered.
Smart ring sizes differ from jewelry sizes and between brands and generations. Use the maker's own sizer before choosing a size; the buyer selects the size for every package here.
RingConn Gen 2 Matte Black, buyer-selected size (US)Sizes 6 to 14. A free sizing kit option ships sizers first; RingConn sizes differ from standard rings and from Gen 3.Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.RingConn: RingConn Gen 3 product page and model comparisonChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Sizes 5 to 14, no half sizes. A free sizing kit option ships plastic sizers first; Ultrahuman sizes may differ slightly from standard US sizes, and Ring AIR sizes carry over.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)US sizes 6 to 14. A replica-ring sizing kit is a separate checkout option; with a known size the ring ships straight away.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ring weight
The published weight of the ring, with the size basis where the manufacturer states it.
Weight changes with size. A single figure without a size basis is not comparable with a range.
RingConn Gen 2 Matte Black, buyer-selected size (US)2 to 3 g, depending on ring size.Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.RingConn: RingConn Gen 3 product page and model comparisonChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)3.3 to 4.8 g, depending on size.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)4 g; size basis not stated.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Width and thickness
The published band width and thickness of the ring.
Thickness can vary by size. These are body measurements, not a comfort or fit guarantee.
RingConn Gen 2 Matte Black, buyer-selected size (US)Width 6.8 mm; thickness 2 mm.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Thickness 2.65 mm, varying by size; width not stated.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Width 7.8 mm; thickness 2.55 mm.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Materials and finishes
The shell and inner-surface materials and the finishes listed for the US.
Finishes can change the coating and the SKU. Scratch and allergy statements are manufacturer claims.
RingConn Gen 2 Matte Black, buyer-selected size (US)Titanium alloy with PVD coating and medical-grade epoxy resin; finishes Royal Gold, Future Silver, Matte Black and Rose Gold.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Titanium unibody with PVD coating, epoxy and polycarbonate; inner surface hypoallergenic plastic and titanium. Colors Raw Titanium, Aster Black, Bionic Gold and Space Silver.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Titanium body with a PVD finish and a hypoallergenic interior; finishes Silver, Obsidian Black, Gold and Rose Gold.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Longest stated ring battery life
The upper end of the manufacturer's battery-life claim for the ring on one charge, without a charging case.
A maker estimate under its own sizes and settings, not a measured result. Read the conditions field for the size basis and the features that shorten it.
RingConn Gen 2 Matte Black, buyer-selected size (US)12 daysUp to 12 days for sizes 12 to 14.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)15 daysUp to 15 days, in Chill Mode.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)8 daysAbout 8 days in power mode.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Battery claim conditions
The size basis, modes and settings behind the battery claim, including any case-assisted figure.
Smaller rings usually carry smaller batteries. Days with a charging case include recharges from the case and are not a ring battery figure.
RingConn Gen 2 Matte Black, buyer-selected size (US)Up to 10 days for sizes 6 to 7, 11 days for sizes 8 to 11 and 12 days for sizes 12 to 14. Enabling the OSA feature may increase power use. The 150 days figure includes charging case recharges.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Turbo Mode about 12 days, Chill Mode more than 15 days; up to 45 days with the PRO Charging Case. Ultrahuman says results vary with usage, settings and environment and gives no size basis.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)About 8 days in power mode and about 4 to 5 days in performance mode with high-frequency measurement; no size basis is stated.The page gives both around five days and four to five days for performance mode.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Charger and charging
The charger type supplied, whether it carries its own battery, and the stated charging time.
Some chargers are size-specific and some cases are not sold separately. A portable case with a battery is different from a dock that needs a cable.
RingConn Gen 2 Matte Black, buyer-selected size (US)Size-specific wireless charging case included; magnetic charging, about 90 minutes to full. The case is not sold separately; a replacement charging dock is.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)PRO Charger case with its own battery and UltraSnap magnetic charging; the case charges by USB-C or 5 W Qi wireless and stores up to a year of ring data in Chill Mode.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Wireless charging case with a USB-C cable for the case; about 30 minutes to full.Whether the case has its own battery is not stated.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Water rating
The water resistance as the manufacturer states it, in ATM, IP or meter terms with any conditions.
A 100 m figure is not a diving rating. IP68 conditions are set by the maker. Follow the stated limits for submersion, diving and heat.
RingConn Gen 2 Matte Black, buyer-selected size (US)IP68 (100 m/328 ft).Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Water resistant to 100 m (328 ft).Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)IP68; Circular says showers, swimming and daily wear are fine.No depth or duration is stated for the IP68 rating.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Sensors listed
The sensor hardware the manufacturer lists, or the signals it says the ring measures where no hardware is listed.
A listed sensor is not a validated measurement. Which metrics appear can depend on the app, a plan or an add-on.
RingConn Gen 2 Matte Black, buyer-selected size (US)Not verified
We have not verified this value. It is not a confirmed no or zero. Check the original source or ask the manufacturer if it affects your choice.
The Gen 2 page lists no sensor hardware. It states continuous monitoring of heart rate, blood oxygen (SpO2), body temperature, sleep, steps and calories.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Temperature sensor, redesigned PPG and 6-axis IMU (accelerometer and gyroscope), covering sleep stages, heart rate, HRV, resting heart rate, SpO2, skin temperature and movement.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)ECG, PPG, temperature sensor and 3-axis accelerometer.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Blood oxygen documented
Whether the manufacturer documents blood oxygen (SpO2) readings for this ring.
Often measured only during sleep and sometimes off by default. It is a wellness reading unless the maker states a regulatory clearance.
RingConn Gen 2 Matte Black, buyer-selected size (US)YesThe page states continuous blood oxygen (SpO2) tracking.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)YesThe FAQ lists SpO2; the explainer says overnight SpO2 comes from the Respiratory Health PowerPlug.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)YesBlood oxygen is listed among the core features.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Works with iPhone
Whether the manufacturer states the ring's app works with iPhone, or states a requirement that excludes it.
The manufacturer's compatibility statement, not a tested result. Minimum iOS versions are in the requirements field where published.
RingConn Gen 2 Matte Black, buyer-selected size (US)YesiOS 17.0 or later.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)YesUltrahuman states the app is on the App Store and syncs with Apple Health; no minimum iOS version is stated.Source · 2026-10-21Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)YesCompatibility is stated as iOS and Android; no minimum version is given.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Works with Android
Whether the manufacturer states the ring's app works with Android phones.
Some rings document only one brand of Android phone, or limit features on others. Read the requirements field.
RingConn Gen 2 Matte Black, buyer-selected size (US)YesAndroid 10.0 or later.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)YesUltrahuman states the app is on Google Play; no minimum Android version is stated.Source · 2026-10-21Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)YesCompatibility is stated as iOS and Android; no minimum version is given.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Phone and app requirements
The stated phone platforms, minimum versions, apps and accounts the ring needs.
Where two manufacturer statements differ, both are recorded. An account is not a subscription, but the ring may not work without it.
RingConn Gen 2 Matte Black, buyer-selected size (US)iOS 17.0+ or Android 10.0+ with Bluetooth 4.0 and above; RingConn app and account. One account pairs with one ring at a time. 5 to 7 days of offline storage.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Ultrahuman app from the App Store or Google Play, with Apple Health sync; minimum phone versions are not stated on the pages read.Sources · 2026-10-21Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Circular app on iOS or Android; minimum phone versions not stated on the page read.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Core features without a subscription
Whether the manufacturer states that the ring's core health features are available without a paid plan.
False means the maker limits most insights to paid members. True can still leave optional paid add-ons, listed in the terms field.
RingConn Gen 2 Matte Black, buyer-selected size (US)YesThe page states no subscription is required and lists the subscription fee as free.Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.RingConn: RingConn Gen 3 product page and model comparisonChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)YesNo subscription fee for ring data; core features are included.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)YesCircular states there is no mandatory subscription.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Subscription terms as stated
What the manufacturer says works with and without a paid plan, and any optional paid add-ons. Prices are not recorded.
A trial month included with a ring is not a permanent entitlement. Plans and their contents can change after purchase.
RingConn Gen 2 Matte Black, buyer-selected size (US)RingConn states no subscription is required and lists the subscription fee as free; no paid plan or paid add-on is described on the Gen 2 page.Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.RingConn: RingConn Gen 3 product page and model comparisonChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Ultrahuman states one purchase gives lifelong access to the ring and data, core features are included and most PowerPlugs are free. Premium PowerPlugs such as Cardio Adaptability and Cycle and Ovulation Pro, and an optional Ultrahuman Max plan, are paid add-ons.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: How the Ultrahuman Ring worksChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman PowerPlugsChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)No mandatory subscription: ECG, blood pressure, sleep, energy, vital alerts, cycle tracking, HRV, temperature, blood oxygen and live measurement are included. A small number of advanced screens are premium and unlocked with coins earned by wearing the ring.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Wellness or regulatory wording
The manufacturer's own wording on whether the ring is a wellness product or holds a regulatory clearance.
Quoted as published. Features such as ECG, apnea or blood pressure trends are not a diagnosis unless the maker states a clearance for that feature.
RingConn Gen 2 Matte Black, buyer-selected size (US)RingConn markets automatic sleep apnea monitoring with a stated 90.7% accuracy; no regulatory clearance is stated. Its Gen 3 page says the product is not a medical device and its apps are not intended to diagnose, treat, cure or prevent any disease.The not-a-medical-device sentence appears on the Gen 3 page, not on the Gen 2 page.Sources · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.RingConn: RingConn Gen 3 product page and model comparisonChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Ultrahuman: Ring PRO is not classified as a medical device and is not intended for managing, treating or preventing diseases or for diagnostic decisions. Its PowerPlugs page lists AFib Detection outside the US, with a USA launch still planned.The Ring PRO page also describes AFib Detection reports; the PowerPlugs page says that PowerPlug has not launched in the USA.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman PowerPlugsChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Circular describes clinical-grade ECG and AFib detection but states no FDA or other regulatory clearance on the page read. It calls the blood pressure reading a wellness estimate, not a diagnosis, needing cuff calibration every 30 days.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
In the box
Items the manufacturer lists in the exact US package.
Sizing kits, spare charging cases, extended protection and paid plans are separate unless the package lists them.
RingConn Gen 2 Matte Black, buyer-selected size (US)Gen 2 smart ring, size-specific charging case, USB-C charge cable, instruction manual and quick start guide.Source · 2026-10-21RingConn: RingConn Gen 2 product pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)Ultrahuman Ring PRO, Ring PRO Charger and a 1 m Type-C to Type-C cable.Sources · 2026-10-21Ultrahuman: Ultrahuman Ring PRO US buy pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.Ultrahuman: Ultrahuman Ring PRO FAQChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Circular Ring 2 Obsidian Black, buyer-selected size (US)Circular Ring 2, wireless charging case, USB-C cable and cleaning cloth; app access for iOS and Android with a digital user guide.Source · 2026-10-21Circular: Circular Ring 2 store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.
Questions to check before buying
RingConn Gen 2 Matte Black, buyer-selected size (US)
Sensor hardware is not listed for Gen 2, and the sleep apnea accuracy figure is a manufacturer claim with no regulatory clearance stated.
RingConn now also sells Gen 3 with different sizing; Gen 2 remains listed on the check date but could be withdrawn.
Ultrahuman Ring PRO Aster Black, buyer-selected size (US)
Battery claims have no stated size basis, and the PRO Charger color shown at checkout is not explained on the page.
The US Ring AIR buy address redirected to Ring PRO on the check date, and AFib Detection is not listed as available in the USA.
Circular Ring 2 Obsidian Black, buyer-selected size (US)
The ECG and AFib claims carry no stated regulatory clearance on the page read; confirm the status with Circular before relying on them.
The 4 g weight and battery figures have no size basis, and the IP68 rating has no published depth or duration. Circular also runs a Ring 3 waitlist.
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