Wellue (Viatom)
Wellue O2Ring
$152.9
Best Pulse Oximeters · head-to-head
Wellue O2Ring vs Contec CMS50D
A sourced, side-by-side comparison. Contec CMS50D is cheaper at $8.99. Every spec and price links to its source.
Contec Medical Systems
Contec CMS50D
$8.99Cheaper
Which is better: the Wellue O2Ring or Contec CMS50D?
On the specs we track, they're closely matched. The Contec CMS50D is the cheaper at $8.99.
As an Amazon Associate we earn from qualifying purchases. Prices verified at capture; live price may differ.
Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | Wellue O2Ring | Contec CMS50D |
|---|---|---|
| US price | $152.9 | $8.99 |
| Brand | Wellue (Viatom) | Contec Medical Systems |
| Released | — | — |
| Spo2 range | 70-100% | 0-100% |
| Spo2 accuracy percent | ±2% (80-100%), ±3% (70-79%) | ±2% (70-100%); ±4% under weak/low-perfusion signal conditions |
| Pulse rate range bpm | 30-250 bpm | 30-250 bpm |
| Display type | On-ring digital display with app-adjustable brightness | LED display |
| Perfusion index | — | No |
| Continuous monitoring | Yes | No |
| Bluetooth | Yes | No |
| Battery life hr | 16 | 24 |
Sources — Wellue O2Ring: getwellue.com (verified 2026-08-01). Contec CMS50D: contecmedsystems.com (verified 2026-08-01).
What's the difference between the Wellue O2Ring and Contec CMS50D?
Where the two actually differ on the specs we track (6 of 8). Matching specs are omitted.
- Spo2 range: Wellue O2Ring 70-100% vs Contec CMS50D 0-100%
- Spo2 accuracy percent: Wellue O2Ring ±2% (80-100%), ±3% (70-79%) vs Contec CMS50D ±2% (70-100%); ±4% under weak/low-perfusion signal conditions
- Display type: Wellue O2Ring On-ring digital display with app-adjustable brightness vs Contec CMS50D LED display
- Continuous monitoring: Wellue O2Ring true vs Contec CMS50D false
- Bluetooth: Wellue O2Ring true vs Contec CMS50D false
- Battery life hr: Wellue O2Ring 16 vs Contec CMS50D 24