Dimensions
Size comparison
C21CS3
| C21 | CS3 | Difference | |
|---|---|---|---|
| Height | 46.5 mm | 43.9 mm | +2.6 mm |
| Width | 46.5 mm | 35.4 mm | +11.1 mm |
| Thickness | 13 mm | 11.3 mm | +1.7 mm |
Drawn to the same scale from the official dimensions (front and side).
Why is C21 better than CS3?
- Pixel density386 ppi vs 218 ppi+77%
- Resolution (width)360 px vs 240 px+50%
- Battery capacity300 mAh vs 235 mAh+28%
Why is CS3 better than C21?
- Screen size1.32″ vs 1.69″+28%
- Thickness13 mm vs 11.3 mm+15%
Specifications
Side by side
| Design & durability | ||
| Case size | 46 mm | 44 mm |
| Weight | — | 38 g |
| Thickness | 13 mm | 11.3 mm |
| Height | 46.5 mm | 43.9 mm |
| Width | 46.5 mm | 35.4 mm |
| Case material | — | Plastic / polymer |
| Lens / cover glass | Corning Gorilla Glass | — |
| Ingress protection | IP68 | IP68 |
| Water resistance (IPx) | IPx8 | IPx8 |
| Colours | Black, Silver | Black, Pink, Green, Purple, Blue |
| Display | ||
| Screen size | 1.32″ | 1.69″ |
| Display technology | LCD | LCD |
| Panel | TFT LCD | IPS LCD |
| AMOLED / OLED display | No | No |
| Resolution (width) | 360 px | 240 px |
| Resolution (height) | 360 px | 280 px |
| Pixel density | 386 ppi | 218 ppi |
| Refresh rate | 60 Hz | 60 Hz |
| Battery | ||
| Battery capacity | 300 mAh | 235 mAh |
| Battery type | — | Li-Ion |
| 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 | No |
| Platform | ||
| Operating system | Proprietary OS | Proprietary |
| Platform | Proprietary | Proprietary |
| Chipset | — | Realtek 8762DK |
