LifeLine Speed & Cadence - Bluetooth 4.0 & ANT+Keep track of your speed and RPM (revolutions per minute) with the LifeLine Speed and Cadence Sensors which are both Bluetooth 4.0 and ANT+ compatible.The sensors are easy to install on to your bike’s frame. Simply mount the speed sensor to the centre of the rear wheel hub and the cadence sensor to the inside of the crank arm. You can then wirelessly connect the sensors to devices such as your GPS computer or smartphone computer which allows you to accurately record your speed and cadence data. Installation instructions are included.FeaturesIPX7 water resistant (waterproof up to 5ft)Operating range: 2-60mph/ 18-220 RPMCR2032 batteries fitted (1 in each)Size: 28mm diameterWeight: Each sensor weighs approximately 10g (inclusive of mount and elastic band)Battery Life: approximately 12 months based on 1 hour everyday useBuy LifeLine Cycle GPS from Chain Reaction Cycles, the World’s Largest Online Bike Store.