4.1Display3.7
5.0Health tracking5.0
2.5Smart features3.9
Why is C21 better than Smart Watch 2?
- Pixel density386 ppi vs 207 ppi+86%
- Resolution (width)360 px vs 240 px+50%
- Battery capacity300 mAh vs 230 mAh+30%
Why is Smart Watch 2 better than C21?
- Screen size1.32″ vs 1.8″+36%
- SpeakerNo · C21: Yes
Specifications
Side by side
| Design & durability | ||
| Case size | 46 mm | — |
| Thickness | 13 mm | — |
| Height | 46.5 mm | — |
| Width | 46.5 mm | — |
| Case material | — | Plastic / polymer |
| Lens / cover glass | Corning Gorilla Glass | — |
| Ingress protection | IP68 | IP68 |
| Water resistance (IPx) | IPx8 | IPx8 |
| Colours | Black, Silver | Black |
| Display | ||
| Screen size | 1.32″ | 1.8″ |
| Display technology | LCD | LCD |
| Panel | TFT LCD | IPS LCD |
| AMOLED / OLED display | No | No |
| Resolution (width) | 360 px | 240 px |
| Resolution (height) | 360 px | 286 px |
| Pixel density | 386 ppi | 207 ppi |
| Refresh rate | 60 Hz | 60 Hz |
| Battery | ||
| Battery capacity | 300 mAh | 230 mAh |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | Yes |
| Sensors | Accelerometer, heart rate, SpO2, blood pressure | Accelerometer, heart rate, SpO2 |
| Sports & navigation | ||
| Built-in GPS | No | No |
| Connectivity | ||
| NFC payments | No | No |
| LTE (cellular) | No | No |
| eSIM | No | No |
| Bluetooth | 5 | 5.1 |
| Smart features | ||
| Speaker | No | Yes |
| Platform | ||
| Operating system | Proprietary OS | Proprietary OS |
| Platform | Proprietary | Proprietary |
