Provides real-time, accurate heart rate to compatible mobile training apps, including Polar Beat and Polar Flow apps * Uses Bluetooth Smart technology providing ECG-accurate heart rate to any Bluetooth Smart ready device utilizing standard heart rate profile * Compatible with the latest iPhones, iPod touch (5th generation), iPad (3rd & 4th generation), iPad mini and iPod Nano (7th generation) * User replaceable battery; For optimal battery life, detach transmitter from chest strap after every use * Also uses GymLink to connect with the majority of Polar heart rate monitors on the market and with compatible gym equipment