The contenders
Side by side
Stock photoThe only one a US buyer can get
Ultrahuman Ring PRO
No subscriptionUS pre-order6.9/10Redesigned to clear the patent claim that banned the AIR, and cleared for US import by CBP ruling H354023. Up to 15 days claimed, 45 with the case.
See it at UltrahumanSold by the maker, not on Amazon. Plain link: we don't earn on it.
Stock photoNot sold to US buyers
Ultrahuman Ring AIR
No subscriptionBrand store only6.4/10Lighter and thinner at 2.4-3.6 g, but still covered by the August 2025 ITC exclusion order and absent from Ultrahuman's US store. Listed here for reference only.
See it at UltrahumanSold by the maker, not on Amazon. Plain link: we don't earn on it.
Stock photoThe no-fee ring you can buy today
RingConn Gen 2
No subscription8.2/10No subscription, 10-12 days a charge plus a case rated at up to 150 days, on Amazon with Amazon's returns, and a settled US legal position.
Check price · Amazon#ad · Price set by Amazon · How we make money for the link to RingConn Gen 2

The answer is legal, not technical
Most comparisons on this site come down to fees, battery or evidence. This one comes down to a patent case, so it is worth stating the sequence plainly.
Oura filed a patent complaint at the US International Trade Commission over smart ring hardware design. In August 2025 the ITC issued exclusion and cease-and-desist orders against Ultrahuman, which stopped it importing and selling its rings in the United States. Ultrahuman's response was not an appeal but a redesign: the Ring PRO, built around a titanium unibody architecture intended to sit outside the patent claim. US Customs and Border Protection ruling H354023, dated March 6, 2026, cleared that redesigned ring for import (CBP ruling H354023), and Ultrahuman opened US pre-orders the same month (Ultrahuman press release, Athletech News).
The clearance applies to the redesign, not to the old ring. When we checked Ultrahuman's US store in September 2026, the only ring offered to a US shopper was the Ring PRO (Ultrahuman US). The AIR is still sold on Ultrahuman's global store — and that page carries a warning most buyers skim past: the stock there is “compliant with Indian laws and regulations,” it is your responsibility “to verify, with your local regulatory or competent authorities, whether the Ultrahuman Ring AIR you intend to order or have ordered can be legally imported and used in your country of residence,” and you owe any import fees (Ultrahuman global FAQ).
Side by side
Both rings' own published figures, each cell linked to the page it came from.
The battery gap
This is the headline upgrade and it is a big one. Ultrahuman rates the Ring AIR at “4 to 6 days on a full charge” from a 24 mAh cell, with about 180 minutes needed to fill it from empty. The Ring PRO claims up to 15 days — Ultrahuman breaks that down as roughly 12 days in “Turbo Mode” and more than 15 in “Chill Mode” — and up to 45 days total with the PRO Charging Case included in the box.
Two caveats belong next to those numbers. First, every one of them is the maker's claim, measured “under specific conditions,” in Ultrahuman's own words. Second, the AIR's FAQ is candid about what happens later: about 500 charge cycles, then “a gradual reduction in battery life” after one to two years, with battery replacements not covered beyond the warranty period. Ultrahuman is the only ring maker we found that publishes a cycle figure at all, which we credit it for in our battery lifespan guide. We did not find a matching cycle figure for the PRO.
For context on the third column: RingConn claims 10-12 days for the Gen 2 and ships a case it rates at up to 150 days of top-ups, which is a different kind of answer to the same problem. Our battery life guide reads every claim on the market with its fine print attached.
Size, weight and fit
The AIR is the smaller object: 2.4 to 3.6 grams depending on size, and 2.45 to 2.8 mm thick. Ultrahuman marketed that thinness hard, and if you have worn one you know it genuinely disappears. The PRO carries more battery, so it is not the featherweight the AIR was.
The useful news for anyone upgrading: both rings use the same sizing. Ultrahuman's PRO page says plainly, “If you already know your Ultrahuman Ring AIR size, your Ring PRO will fit just the same,” and both run sizes 5 to 14 with a free sizing kit and no half sizes. Both also warn that Ultrahuman sizes “may differ slightly from standard US ring sizes” — the usual warning from every brand, and the reason our sizing guide tells you to use the kit even if you think you know your size. Sizes do not transfer between brands either: sizing compared shows how far apart they are.
What carried over unchanged
- No subscription. Both rings: “no recurring subscription fees for accessing your data.” Both sell optional paid PowerPlugs and optional UltrahumanX coverage instead, which is a model we are much happier with than a compulsory membership — see Ultrahuman's subscription policy.
- A 100 m water rating. The AIR's FAQ names swimming, showering and scuba diving, while advising against staying submerged for more than 30 minutes at a stretch. The PRO is rated 100 m / 328 ft. Our waterproofing guide reads what those ratings actually permit.
- Titanium, and the same size range. The AIR used titanium with a tungsten carbide carbon coating; the PRO moved to a titanium unibody, which is the part that mattered legally. Both cover sizes 5-14 with a free kit.
- The same app and the same metrics. Heart rate, HRV, temperature, SpO2, sleep stages, movement and recovery. The AIR needed a one-time calibration period of up to seven days, and a hard reset restarts it.
What the evidence says (and does not)
If you already own a Ring AIR
You are not affected by the import question — an exclusion order stops new imports, it does not reach into your hand. Ultrahuman has said it continues to support existing rings, and the AIR's FAQ terms still describe its warranty and battery policy.
Three practical notes:
- Your size carries over. Ultrahuman says a PRO in your AIR size will fit the same, so an upgrade does not mean re-sizing.
- Expect the battery to fade. About 500 cycles, then gradual decline after one to two years, and replacements are not covered beyond the warranty period. Our battery swelling guide covers what to watch for and when to stop wearing it.
- Upgrading is not urgent unless battery is your complaint. The PRO's case is genuinely the biggest change. The sensors and the app are not a different experience.
Who should buy what
- US buyer who wants an Ultrahuman ring: the Ring PRO, from Ultrahuman's US store, and check the ship date before you order.
- US buyer who wants a no-fee ring this week: the RingConn Gen 2. Our no-fee ranking explains why it leads.
- Existing AIR owner: keep it until the battery annoys you, then move to the PRO in the same size.
- Anyone buying on published evidence: neither Ultrahuman ring. Read Oura vs Ultrahuman for the trade you would be making.
In detail
The contenders, in full
Stock photoThe only one a US buyer can get
Ultrahuman Ring PRO
Redesigned to clear the patent claim that banned the AIR, and cleared for US import by CBP ruling H354023. Up to 15 days claimed, 45 with the case.
Published specsResearched · not tested by us
How the 6.9 score breaks down
- Cost of ownership (3 years) (30%)
- 9
- Evidence of accuracy (25%)
- 2
- Battery (claimed) (15%)
- 10
- Sizing & fit (10%)
- 9
- Data ownership (10%)
- 8
- Platform support (10%)
- 5
What the specs support
- No required subscription
- Longest claimed battery we found: up to 15 days, 45 with the included case
- Free sizing kit; sizes 5-14
- Titanium unibody, 100 m water rating
Where it falls short
- US pre-order only, from Ultrahuman's store; US ship dates have slipped more than once
- Not sold on Amazon.com, so we don't earn on it (and you can't use Amazon's returns)
- No independent validation; Ultrahuman's only published data is an in-house pilot on the older Ring AIR
- Optional paid PowerPlugs for some features
Skip this if…
…You need a ring now or want to buy through Amazon: it's a brand-store pre-order with a ship date that has moved.
Sold by the maker, not on Amazon. Plain link: we don't earn on it.
Stock photoNot sold to US buyers
Ultrahuman Ring AIR
Lighter and thinner at 2.4-3.6 g, but still covered by the August 2025 ITC exclusion order and absent from Ultrahuman's US store. Listed here for reference only.
Published specsResearched · not tested by us
How the 6.4 score breaks down
- Cost of ownership (3 years) (30%)
- 9
- Evidence of accuracy (25%)
- 3
- Battery (claimed) (15%)
- 5
- Sizing & fit (10%)
- 9
- Data ownership (10%)
- 8
- Platform support (10%)
- 5
What the specs support
- No subscription, and Ultrahuman calls it "lifelong access to both the ring and your personal data"
- Lighter and thinner than the Ring PRO: 2.4-3.6 g at 2.45-2.8 mm
- Same 5-14 size range and free sizing kit, and Ultrahuman says a PRO fits the same as an AIR
- The only Ultrahuman ring with any published accuracy data, thin as that data is
Where it falls short
- A US buyer cannot buy it: the exclusion order stands and Ultrahuman's US store does not list it
- 4-6 days a charge, against up to 15 claimed for the Ring PRO
- No charging case in the box, and a 180-minute full charge
- The global store puts import legality, duties and taxes on you
Skip this if…
…You are shopping from the United States. This ring is not on sale to you, and the Ring PRO is the model Ultrahuman redesigned so it could be.
Sold by the maker, not on Amazon. Plain link: we don't earn on it.
Stock photoThe no-fee ring you can buy today
RingConn Gen 2
No subscription, 10-12 days a charge plus a case rated at up to 150 days, on Amazon with Amazon's returns, and a settled US legal position.
Published specsResearched · not tested by us
| Subscription | None ("No Subscriptions") |
|---|---|
| Battery (claimed) | 10-12 daysMaker's claim |
| Charging case | Included; "Extended Up to 150 Days With Charging Case"Maker's claim |
| Sizes | 6-14 |
| Sizing kit | Complimentary |
| Phones | iOS 17.0+ and Android 10.0+ |
| Water resistance | IP68 (100 m / 328 ft) |
| Materials | Titanium alloy with medical-grade epoxy resin |
| HSA/FSA | Eligible through Flex |
| Warranty (US) | 1 year (non-EEA); normal battery capacity loss excluded; optional 2- or 3-year protection in the US |
| Features | "Automatic sleep apnea monitoring" with a "90.7% Sleep Apnea Monitoring Accuracy" claim (maker's claim; not a diagnosis)Maker's claim |
| US availability | Listed on Amazon.com |
How the 8.2 score breaks down
- Cost of ownership (3 years) (30%)
- 10
- Evidence of accuracy (25%)
- 5
- Battery (claimed) (15%)
- 9
- Sizing & fit (10%)
- 9
- Data ownership (10%)
- 8
- Platform support (10%)
- 9
What the specs support
- No subscription
- The charging case turns a 10-12 day ring into a months-between-outlets ring (maker's claim)
- A 2026 preprint compared it with a Polar H10 at rest: heart rate bias -0.42 bpm
- iOS and Android, free sizing kit
Where it falls short
- The chest-strap study is a preprint, seated only, and not peer-reviewed
- A reviewer found it read heart rate high during runs compared with a chest strap
- Needs iOS 17 or Android 10 or newer
- Sleep apnea figure is RingConn's own claim
Skip this if…
…You want workout heart rate you can trust on runs: a reviewer found it read high against a chest strap. Wear a strap for training.
#ad · Price set by Amazon · How we make money for the link to RingConn Gen 2
How we scored this
Rings we claim to have lab-tested: 0
Plenty of ring reviews say they wore everything they rank. We haven't, and we say so. Every pick here is labeled Researched: we read each brand's fee policy, spec sheet, sizing and warranty pages, and the published studies that tested the ring (or its predecessor) against a chest strap, an ECG or a sleep lab, then scored it on a public rubric. Every figure links to where it came from, and maker performance numbers are labeled “maker's claim.”
Scores are editorial judgments from that documented research, not test results. Commissions never set a score or decide a pick. The rubric and its weights are published.
What changed
- Published.
Questions
Frequently asked
Can I buy the Ultrahuman Ring AIR in the US?
What is the difference between the Ultrahuman Ring PRO and Ring AIR?
Will my Ring AIR size fit the Ring PRO?
Does either ring charge a subscription?
Is my Ring AIR still supported now that the PRO has launched?
Which has better accuracy, the PRO or the AIR?
Receipts
Sources
- Ultrahuman US: Ring PRO buy page (price, ship date, subscription, battery, sizes) (checked 2026-09-19)
- Ultrahuman global store: Ring AIR buy page (weight, thickness, battery, charge time, import responsibility) (checked 2026-09-26)
- Ultrahuman: Ring AIR FAQ (warranty, battery aging, compatibility) (checked 2026-09-19)
- Ultrahuman US store: the only ring offered to US buyers is the Ring PRO (checked 2026-09-26)
- Ultrahuman US: Ring FAQ (ProRelease Technology, BLE 5.3) (checked 2026-09-19)
- Ultrahuman US: Terms of Sale, Ultrahuman Ring (12-month limited warranty) (checked 2026-09-19)
- Ultrahuman US: HSA/FSA page (checked 2026-09-19)
- Ultrahuman US: UltrahumanX FAQ (checked 2026-09-19)
- Ultrahuman press release: Ring PRO open for US pre-orders (Mar 24, 2026) (checked 2026-09-19)
- Ultrahuman: in-house pilot study, sleep heart rate sensing (not peer-reviewed) (checked 2026-09-19)
- U.S. Customs and Border Protection ruling H354023 (Mar 6, 2026) (checked 2026-09-19)
- Athletech News: Ultrahuman can sell in the US market again following ITC resolution (checked 2026-09-26)
- The Gadgeteer: the banned smart ring comes back (Mar 2, 2026) (checked 2026-09-19)
- the5krunner: Ultrahuman Ring PRO (May 6, 2026) (checked 2026-09-19)
- Oura: ITC case outcome and RingConn license (Oct 2025) (checked 2026-09-19)
- Oura: second ITC action (Samsung, Zepp, Reebok, Nexxbase) (checked 2026-09-19)
- Android Central: we compared smart ring heart rate data with smartwatches (workout heart rate test) (checked 2026-09-26)
- RingConn: Gen 2 product page (checked 2026-09-19)
- RingConn: Oura and RingConn multi-year patent licensing agreement (checked 2026-09-19)
We haven't worn or lab-tested the rings on this page and we don't pretend to. Fees come from each brand's own policy pages (with the date we checked), specs from maker pages and listings, and accuracy claims from named, published studies. Hardware prices are set by Amazon and change daily, so we don't print them. Where a figure isn't published, we say so. Read the full method.




