Dimensions
Size comparison
C21C28
| C21 | C28 | Difference | |
|---|---|---|---|
| Height | 46.5 mm | 58.3 mm | −11.8 mm |
| Width | 46.5 mm | 46.1 mm | +0.4 mm |
| Thickness | 13 mm | 13.3 mm | −0.3 mm |
Drawn to the same scale from the official dimensions (front and side).
Why is C21 better than C28?
- Pixel density386 ppi vs 250 ppi+54%
- Resolution (width)360 px vs 320 px+12%
- Thickness13 mm vs 13.3 mm+2%
Why is C28 better than C21?
- Screen size1.32″ vs 2.02″+53%
- SpeakerNo · C21: Yes
- Battery capacity300 mAh vs 410 mAh+37%
Specifications
Side by side
| Design & durability | ||
| Case size | 46 mm | 58 mm |
| Weight | — | 44.5 g |
| Thickness | 13 mm | 13.3 mm |
| Height | 46.5 mm | 58.3 mm |
| Width | 46.5 mm | 46.1 mm |
| Lens / cover glass | Corning Gorilla Glass | — |
| Water resistance | — | 1 ATM |
| Ingress protection | IP68 | — |
| Water resistance (IPx) | IPx8 | — |
| Colours | Black, Silver | Black, Green |
| Display | ||
| Screen size | 1.32″ | 2.02″ |
| Display technology | LCD | LCD |
| Panel | TFT LCD | TFT LCD |
| AMOLED / OLED display | No | No |
| Resolution (width) | 360 px | 320 px |
| Resolution (height) | 360 px | 390 px |
| Pixel density | 386 ppi | 250 ppi |
| Refresh rate | 60 Hz | 60 Hz |
| Battery | ||
| Battery capacity | 300 mAh | 410 mAh |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | Yes |
| Sensors | Accelerometer, heart rate, SpO2, blood pressure | Accelerometer, heart rate, SpO2, blood pressure |
| Sports & navigation | ||
| Built-in GPS | No | No |
| Connectivity | ||
| NFC payments | No | No |
| LTE (cellular) | No | No |
| eSIM | No | No |
| Bluetooth | 5 | — |
| Smart features | ||
| Speaker | No | Yes |
| Platform | ||
| Operating system | Proprietary OS | Proprietary OS |
| Platform | Proprietary | Proprietary |
