The Saris Magnetless Speed or Cadence Sensor harnesses the advances in accelerometer technology to leave the magnet in the dust, along with your competition. This sensor can be used for either speed or cadence and gives you the edge and the easiness to simply install the battery, orient the sensor to program it for speed or cadence, and mount it on either the non-drive side crank arm or the bike's hub, front or rear. Its light Indicator will turn white for Speed and green for cadence. That's it, no magnet, no problem. Stop wasting time lining up old magnets and sensors and use that time to crush Strava segments with the Saris Magnetless Speed or Cadence Sensor!