i get new one as gift 🎁 that's why i sell it otherwise no problem in it.
working video also uploaded.

Description
Functions:- 1.Heart Rate Monitor 2.Sedentary reminder 3.Calories 4.Time 5.Alarm 6.Anti-lost 7.Distance calculation 8.Step Monitor 9.Call Alert 10.Wrist sense Pre-requisites for use:- Your mobile phone Bluetooth version must be Bluetooth 4.0 or higher, IOS version must be iOS 7.1 or above, Android version must be Android 4.3 or above. Working:- To connect the smart band to mobile phone, you need to connect the current mobile successfully via Bluetooth. Click unbind icon and band has been successfully connected with the device. Specifications HR sensor:- weight : 7g Battery type : rechargeable Li battery , Battery capacity :40mAh. Note:- To charge this fitness band you simply need to connect it with the charger charging will get start automatically . Data sync: Bluetooth 4.0 Working temperature: -10c to 50c Waterproof: Not for swimming or diving Standby time: 15 days & above this product uses professional Bluetooth RF signal and custom algorithm, the accuracy can reach 100 %.