Yoo YX3600BK 2 BlueTooth Smart Activty Tracker (Black) Bluetooth Smart wireless activity tracker Tracks minutes moved, daily steps, distance and calories-burned LEDs light up to track progress 6+ month battery life Lithium Ion CR2032 battery included Easy-to-use Wireless Activity Tracker Track Daily Steps, Distance & Calories-burned Leds Light Up To Track Progress Wave The Leds In The Air To Display Step Count Instantly Slip On To A Shoe Or Belt Loop Or Slip Into A Pocket Or Bra For Portable Convenience