Features:Great Craftsmanship: 0.42 inch OLED display screen, clearly showing the date, clock and battery power. Just 19g, it looks fashion and thin. Silicone watchband with adjustment holes, wear it comfortable and valuable.Heart Rate Monitoring: Optimize multiple motion algorithms to ensure the accuracy of heart rate, when moving, you can look at your heart rate data and help you keep track of your physical condition.Real-time Pedometer: Intelligent computing moves the pace, time, distance and calories consumed, and generates daily, weekly, monthly exercise statistics.Sleep Monitoring: Monitor your sleeping condition and analyze sleeping quality, help you better understand your sleep patterns.Call/Message Reminder: M4 smart band will vibrate to remind you of calls and messages, support SMS, QQ, Wechat, Whatsapp.Waterproof: Effective prevention of living water and exercise sweating.Convenient USB Charging: This host adopts the USB charge port, so you can charge it anytime and anywhere.Function:Blood Pressure: Simulate blood pressureBlood Oxygen Heat RateSports Plan: Training planTime: OLED display 24h formulaPedometers: Movement stepCall Alert: shockSleep Monitoring: Monitor stepAlarm Prompt: Set through AppLow Voltage Reminder:Vibration reminder