Ultrahuman
Ultrahuman Ring AIR
$349Cheaper
2 sellers$349read
Released 2023-06
Best Smart Rings · head-to-head
Ultrahuman Ring AIR vs Circular Ring 2
A sourced, side-by-side comparison. Ultrahuman Ring AIR is cheaper at $349. Every spec and price links to its source.
Circular
Circular Ring 2
$379
2 sellers$349under listread
Released 2025-08
Which is better: the Ultrahuman Ring AIR or Circular Ring 2?
On the specs we track, they're closely matched. The Ultrahuman Ring AIR is the cheaper at $349.
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec |  Ultrahuman Ring AIR |  Circular Ring 2 |
|---|---|---|
| US price | $349 | $379 |
| Brand | Ultrahuman | Circular |
| Released | 2023-06 | 2025-08 |
| Material | Titanium outer shell with tungsten carbide carbon coating; medical-grade hypoallergenic inner layer | Titanium (PVD coating on premium finishes) |
| Weight (g) | 2.4-3.6 | 3 |
| Battery days | 6 | 8 |
| Spo2 | Yes | Yes |
| Temperature sensor | Yes | Yes |
| Ecg | No | Yes |
| Subscription required | No | No |
| Water resistance (m) | 100 | — |
Sources — Ultrahuman Ring AIR: ultrahuman.com (verified 2026-11-05). Circular Ring 2: shop.circular.xyz (cited since 2026-10-12; read 2026-06-15 at another shop.circular.xyz page).
What's the difference between the Ultrahuman Ring AIR and Circular Ring 2?
Where the two actually differ on the specs we track (4 of 8). Matching specs are omitted.
- Material: Ultrahuman Ring AIR Titanium outer shell with tungsten carbide carbon coating; medical-grade hypoallergenic inner layer vs Circular Ring 2 Titanium (PVD coating on premium finishes)
- Weight (g): Ultrahuman Ring AIR 2.4-3.6 vs Circular Ring 2 3
- Battery days: Ultrahuman Ring AIR 6 vs Circular Ring 2 8
- Ecg: Ultrahuman Ring AIR false vs Circular Ring 2 true
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
Ultrahuman Ring AIR
Two whitelisted testers (TechRadar, Digital Trends) each wore the Ring Air hands-on for a full month in August 2023 and agree it is exceptionally light, comfortable to wear 24/7, accurate against wrist wearables in side-by-side testing, and free of any subscription. Both also flag that it scratches within weeks of gym/daily wear and packs in a lot of data to comb through, though they split on how usable the app is. (2 sourced reviews, 2 lab-tested.)
Praised: Exceptionally light and comfortable to wear 24/7, including overnight; Health/sleep/heart-rate data tracks accurately vs wrist wearables in side-by-side testing; No monthly subscription fee, unlike Oura and Whoop.
Flagged: Titanium coating scratches within a few weeks of gym/daily wear; A lot of data to comb through; the app is data-dense; Expensive at $349.
Circular Ring 2
No sourced tester review yet.