Xiaomi MGW4024GL Mi Band 2 Miband with OLED Display Wristband Bracelet Smart Heart Rate Fitness Activity Tracker 20 Days Standby Time, Black US ADI sensors to detect movement and sleep quality and real-time monitoring of heart rate OLED display screen with touch button control Monitor your activity levels, track walking distance and calculate calories burned Automatic sleep monitoring analyzes your sleep quality Monitor your activity levels, track walking distance and calculate calories burned