Smart Sensor Correction Device Hunchback Back Posture To Correct Children And Students Sitting Posture Vibration Reminder describe: Function: Intelligent sitting posture reminder, strong vibration reminder, and count the number of mistakes, can slow down the habit of hunchback through the number of mistakes within a period of. The correction process is not easy, it takes persistence to be effective This is through physical correction, and the effect of actively straightening the back is better! Material: ABSand elastic shoulder strap Fully charged usage time: 15 days Charging output interface: standard V8 interface Charging time: 2 hours (about 2 hours) Built-in battery specification: 500mA or 3.7V include: 1x Smart back orthosis Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.