The Xiaomi MiBand bracelet has function of recording the sport date in every day, sleep quality monitoring, smart alarm clock wake up. You can view real-time physical activity through mobile applications, monitoring the effect of walking and running, you can identify more sport through the clouds. Xiaomi bracelet can automatically determine whether to sleep, deep sleep and light were recorded and summarized sleep time to help users monitor their sleep quality. Parameters: Extremely narrow 8mm Battery Battery capacity: 41mAh 30-day standby power Input Current: 25mA Input voltage: DC 5.0V Metal surface material: Full magnesium - alloy Body shell: Polycarbonate ADI military force sensor Dialog's leading Bluetooth chip Wristband Material: Dow Corning TPSIV Adjustable wrist strap length: 157mm to 205mm Water resistant (IP67) . Function: Record daily motion data, Xiaomi bracelet to help you record all-day event, calculate walking distance, and calorie consumption. Smart Vibration alarm clock, simulation wake up naturally Status: The user can set the alarm on the APP, in front of the preset alarm within 30 minutes, with a slight vibration to wake you from a shallow sleep, when to wake up slowly shallow sleep, naturally wake up closer. Automatic sleep monitoring. Bluetooth real-time synchronization to APP: analysis of movement sleep data, providing health advice. Reminder phone calls: phone calls, the bracelet can be within a certain range (in theory, should be a Bluetooth sensing range 10-15M) sensing phone calls, and in case you have not turned on within a certain time, the bracelet will vibrate and flash prompts you through. In the outdoor noisy environment, even if the phone placed inside the bag, still do not worry about missing important calls.