Xiaomi Mi Band Smart Wristband Bracelet Fitness Wearable Tracker Waterproof IP67 MiBand Smartband for IOS 7.0 Android 4.4 (mi band + black wrist strap) Understand your every move. Military-grade sensor, 30 day battery Monitor your activity levels, track walking distance and calculate calories burned. Achieve the daily exercise targets you set and work towards a healthier lifestyle! Automatic sleep monitoring analyzes your sleep quality. Smart vibration alarm A gentle nudge to start your day Mi Band's smart vibration alarm wakes you gently 30 minutes before the alarm goes off. Wake up gradually and naturally from a deep sleep, so when the alarm sounds, you are ready to jump straight into your day. Sync with the app to analyze your fitness and sleep activities to help you improve your lifestyle.