Boost your cycling performance with Polar Bluetooth Smart cadence and speed sensors. Find out what your most efficient pedaling rate is and measure your speed and distance accurately. The sensors included in this set work with Bluetooth Smart technology and consume only a little energy. Light yet tough, and easy to attach. Compatible with Polar V800 , Polar V650, popular cycling apps, the iPhone 4S and later and select Android devices using Android 4.3 or later