Smart Hand Band

M4 Fitness Smart band: If you're a fitness freak and love keeping a track of the calories burnt, sleep cycle, and heart rate, and then the M4 Smart Band is what you need. This smart band works as a heart rate tracker, fitness watch, and an activity tracker.M4 waterproof Smart fitness Band compatible with Bluetooth or Heart Rate Sensor. It is compatible to devices having Bluetooth version 4.0 and below in smartphones, Tablets and PC's and also support Android.