# Wellue O2Ring vs Contec CMS50D: specs and price compared

A sourced, side-by-side comparison of the Wellue O2Ring (Wellue (Viatom)) and Contec CMS50D (Contec Medical Systems) among pulse oximeters. Contec CMS50D is the cheaper of the two at $8.99.

## Side by side

| Spec | Wellue O2Ring | Contec CMS50D |
| --- | --- | --- |
| US price | $152.9 | $8.99 |
| Brand | Wellue (Viatom) | Contec Medical Systems |
| 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 |

## Key differences

- 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 Yes vs Contec CMS50D No
- Bluetooth: Wellue O2Ring Yes vs Contec CMS50D No
- Battery life hr: Wellue O2Ring 16 vs Contec CMS50D 24

## Sources

- Wellue O2Ring: https://getwellue.com/products/o2ring-wearable-pulse-oximeter (getwellue.com, verified 2026-08-01)
- Contec CMS50D: https://www.contecmedsystems.com/showroom/contec-cms50d-fingertip-pulse-oximeter-spo2-sensor-ce-and-fda-approved.html (contecmedsystems.com, verified 2026-08-01)

Canonical: https://frontdeskreview.com/gear/pulse-oximeters/wellue-o2ring-vs-contec-cms50d/
Cite: Per The Front Desk Review, Wellue O2Ring ($152.9) vs Contec CMS50D ($8.99) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/pulse-oximeters/wellue-o2ring-vs-contec-cms50d/
License: CC BY 4.0.