Ultrahuman
Ultrahuman Ring AIR
$349Cheaper
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
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 2026-06-15). Circular Ring 2: shop.circular.xyz (verified 2026-06-15).
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.