The Garmin wireless cadence sensor monitors your pedalling cadence as you ride. Simply attach the cadence sensor and ride. With no magnets or other exposed parts to line up, the cadence sensor is easy to install, maintain and move between bikes.The cadence sensor fastens to any crank arm size and measures pedal strokes per minute so you can get the most out of your training. The Garmin cadence sensor is compatible with a number of Garmin Edge GPS bike computers and Forerunner GPS running/sports watches including Garmin Edge 1000, Edge 500, Edge 510, Edge 705, Edge 800, Edge 810, Forerunner 305, Forerunner 310XT, Forerunner 610, Forerunner 910XT, FR 60 and FR70. Combine the Garmin cadence sensor with the Garmin speed sensor (not included) to improve your personal best or see where your stand against the pros. Water-rated to 1 ATM; ANT+ wireless connectivity does not work underwater.