If you're a fitness freak and love keeping a track of the calories burnt, sleep cycle, and heart rate, and then the M2 Smart Band is what you need. This smart band works as a heart rate tracker, fitness watch, and an activity tracker. M2 water proof Smart fitness Band compatible with Bluetooth or Heart Rate sensor. It is compatible to devices having Bluetooth version 4. 0 and below in smart phones, Tablets and PC's and also support Android and IOS. It has features such as calling function which enables you make a call and disconnect it, you can also send and receive messages through it but only supported to Android Phones for which you need to download app. Functions: 1. Heart Rate Monitor 2. Sedentary reminder 3. Calories 4. Time 5. Alarm 6. Anti-lost 7. Distance calculation 8. Step Monitor 10. Call Alert 11. Wrist sense Pre-requisites for use: , 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. Select unbind icon and band has been successfully connected with the device. Specifications HR sensor: Silicon labs Si1142 Host weight: 7g Battery type: rechargeable Li battery, Battery capacity: 40mAh. To charge this fitness band you simply need to connect it with the charger charging will get start automatically. Working temperature: -10c to 50c Waterproof: Not for swimming or diving Standby time: 15 days & above this product uses professional Bluetooth RF signal algorithm, the accuracy can reach 100 % and above Package Contents: 1 x Bluetooth Smart Bracelet 1 x User manual 1 x USB Charging cable.