Description:
Brand: xiaomi
Model: Standard version: M2239B1 / NFC version: M2240B1
Main body size: 48*22.5*10.99 mm
Screen size and type:1.62 inch AMOLED screen    
Screen resolution: 192*490
Screen brightness: up to 600nit, supports automatic brightness adjustment
Cover material: 2.5D reinforced glass cover
Case material: PC
Sensor: Optical heart rate and blood oxygen sensor, six-axis motion sensor
Waterproof rating: 5ATM
Wireless connectivity:BluetoothTM BLE 5.1
Vibration motor: Rotor motor
Battery capacity: 190mAh
Battery type: Lithium-ion polymer battery
Charging time: Support fast charging, charging time about 1 hour
Wristband adjustable length: 135-210mm
Wristband material: TPU
System language: Chinese, English
Support system: Android 6.0 or iOS 12.0 and above
Support APP: Xiaomi Sports Health

Packing list:
Bracelet  *1
Charging cable *1