Dimensions
Size comparison
C21C9
| C21 | C9 | Difference | |
|---|---|---|---|
| Height | 46.5 mm | 43 mm | +3.5 mm |
| Width | 46.5 mm | 43 mm | +3.5 mm |
| Thickness | 13 mm | 10 mm | +3 mm |
Drawn to the same scale from the official dimensions (front and side).
Why is C21 better than C9?
- Screen size1.32″ vs 1.28″+3%
- Resolution (width)360 px vs 240 px+50%
- Pixel density386 ppi vs 265 ppi+46%
- Battery capacity300 mAh vs 210 mAh+43%
Why is C9 better than C21?
- Thickness13 mm vs 10 mm+30%
Specifications
Side by side
| Design & durability | ||
| Case size | 46 mm | 43 mm |
| Thickness | 13 mm | 10 mm |
| Height | 46.5 mm | 43 mm |
| Width | 46.5 mm | 43 mm |
| Lens / cover glass | Corning Gorilla Glass | Scratch-resistant glass |
| Ingress protection | IP68 | IP68 |
| Water resistance (IPx) | IPx8 | IPx8 |
| Colours | Black, Silver | Black, Blue, Pink |
| Display | ||
| Screen size | 1.32″ | 1.28″ |
| Display technology | LCD | LCD |
| Panel | TFT LCD | IPS LCD |
| AMOLED / OLED display | No | No |
| Resolution (width) | 360 px | 240 px |
| Resolution (height) | 360 px | 240 px |
| Pixel density | 386 ppi | 265 ppi |
| Refresh rate | 60 Hz | 60 Hz |
| Battery | ||
| Battery capacity | 300 mAh | 210 mAh |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | — |
| Sensors | Accelerometer, heart rate, SpO2, blood pressure | Accelerometer, gyro, heart rate |
| Sports & navigation | ||
| Built-in GPS | No | No |
| Connectivity | ||
| NFC payments | No | No |
| LTE (cellular) | No | No |
| eSIM | No | No |
| Bluetooth | 5 | 5 |
| Smart features | ||
| Speaker | No | No |
| Platform | ||
| Operating system | Proprietary OS | Proprietary OS |
| Platform | Proprietary | Proprietary |
