This Bike Speed&Cadence Sensor consists of a separate Cadence Sensor wired to a Speed+Distance Sensor that has a battery hatch and a bluetoot 4.0 transmitter. The sensor includes two magnets to activate the sensors and cable ties for installation. A.This device is a Bluetooth Smart devicecompatible and applicable with many iOS devicesincluding a) iPhone 4S / iPhone 5 / iPhone 5S / iPhone 5C b) The new iPad / iPad 4 / iPad mini / iPad air c) iPod touch 5 B.In additionthis device is also recommended to work with the following APPs: a) WahooFitness b) Strava c) MapMyRide *All brand names and trademarks are properties of their repective owners.