The pedal cadence magnet should be carefully snapped onto the pedal spindle on the non-drive side crank arm. Titanium or alloy pedal bolts will not attract the magnet but glue can still be used (we recommend epoxy resin or tubular glue). To remove the pedal magnet please use a flat headed screwdriver (elastic around the screwdriver blade can help prevent damage) & carefully pry the magnet away from the pedal. No additional postage for multiple orders. Compatible with the following cycle computers where cadence is a feature: Blackburn Atom, Bikehut Bontrager Bryton Rider Cannondale Cateye Cycleops Echoweel U4 Evodigitals Garmin Forerunner 310XT, Garmin Forerunner 305, Garmin Forerunner 910XT Garmin GSC-10 Edge 500 Edge 510, Edge 605 Edge 705 Edge 800 Edge 810 GPS Halfords Knog Nerd Kurt Kinetic Mavic Planet Bike Polar Raleigh SERFAS Shimano Sigma Sodial Topeak Velochampion, Topeak Trixes VDO Veloset , Veloset Ventura