Xiaomi Mi Smart Band 4 Smart Band Activity Tracker Brand: Xiaomi Notification Function: Displays Japanese for incoming call notifications, email notifications, Line notifications, etc. Settings on the smart band itself are displayed in English. Sensors: Heart rate sensor, gyroscope sensor, acceleration sensor, step counter, heart rate measurement, calorie consumption, sleep detection, waterproof and dustproof functions, Bluetooth connection I am selling this because I have replaced it. The battery life lasted for more than 7 days from a full charge, but this cannot be guaranteed as it depends on usage. The silicone band shows signs of use. The third-party nylon band is almost unused. The USB charger is a third-party product that allows charging without removing the band. The Zepp Life app on your smartphone is required to use it.