M3 smart wristband fitness tracker heart rate monitor instant message incoming call alert waterproof 5atm OLED touch screen weather forecast 30 skills. Weight is only 20gm wechat, caller and other content display; temperature changes within three days; event reminder, vibration alarm clock 50 meters swimming waterproof. Swimming, surfing, wearable, 5atm waterproof adds the secondary function of sports, and the sports data is visible in real time. Regardless of running, cycling, walking, you can always understand the physical state of your heart rate, speed and adjust exercise intensity for better results. Meet the standard reminder. Set a small goal. When you complete the goal for the day, the millet bracelet 3 will gently alert you that it is up to date today. All-day health management. 'More accurate step, heart rate, sleep monitoring, sedentary reminder 20 days long battery life, secret unlock, caller ID/rejection. 30 Skills anti-lost design: firmly lock the body, not easy to lose soft skin-friendly material, to wear reminder: in the mifit app, you can set daily needs according to your own situation, choose fitness courses that suit you, and regularly check your week's exercise and sleep data. Size: 17.9 X 46.9 X 12mm wristband length: 247mm adjustable length of wristband: 155 - 216mm battery capacity: 110mah standby time: about 20 days battery type: lithium ion polymer battery input voltage: DC 5.0V input current: 250ma max weight: about 20g (including wristband) waterproof rating: 5atm working temperature: -10c -50c screen size: 0.78 Inches display resolution: 128 x 80 sensors: 3-axis accelerometers, ppg heart rate sensors wireless connection: bluetooth 4.2 Ble version setup requirements: bluetooth 4.0 Android 4.4 Or ios9.0 And above mobile phones unlock function: supports models based on Android 4.4 Or higher miui system, or Android 5.0 Or above, and supports smart lock model.