1. Matching system: HarmonyOS 2 and above, Android 6.0 and above, iOS 9.0 and above 2. Screen: 1.64 inches AMOLED touch color screen, resolution 280x456 3. Battery capacity: 451mAh wireless charging dock 4. Theoretical charging time: about 2.5 hours 5. Theoretical working time: typical usage scenarios can last up to 7 days 6. Body material: aluminum alloy middle frame, plastic + sapphire bottom case 7. Strap material: Viton 8. Strap adaptation circumference: M size 130-160mm L size 161-200mm 9. Bluetooth frequency band: 2.4G 10. Bluetooth protocol: Bluetooth 5.1 11. Sensors: acceleration sensor, gyroscope sensor, optical heart rate sensor, temperature sensor, ALS sensor, differential pressure sensor, Hall sensor, ECG acquisition sensor 12. Operating system: HarmonyOS 13. Support message reminder, voice assistant, alarm clock, timer, OTA software upgrade 14. Waterproof and dustproof: IP68 15. Size: 51x38x13.6mm 16. Weight: about 40.9g (without strap) 17. Functions: blood pressure measurement, ECG acquisition, heart rate monitoring, blood oxygen monitoring, sleep monitoring, breathing training, pressure monitoring, body temperature research, 70+ exercise modes 18. Language support: English 19. Packing list: - Smart Watch (including L size watchband and L size airbag) x 1 - M size airbag (including airbag cover) x 1 - M size watchband x 1 - Independent cover x 1 - L size airbag cover (spare) x 1 - M size airbag cover (spare) x 1 - Charging base x 1 - Quick start x 1 - Wearing guide x 1