Garmin Rally RS100 is tested to the extreme, so you can ride there too. This single-sensing power meter delivers accurate and reliable power data and is easily transferrable between bikes, no matter what bike you're riding or where. Key FeaturesRuggedly Reliable: Rally power meters undergo exhaustive testing to ensure they can stand up to the rigours of everyday riding. Accurate Readings: By precisely measuring your cadence and forces detected on the left pedal, Rally RS100 double the value to provide total power output. Shimano SPD-SL CompatibleTransferrable Spindle: Want to switch between road and gravel? A transferrable spindle can be installed in Rally™ RK road and Rally ™ XC off-road pedal body kits. Battery Life: Ready to keep on rolling, with up to 120 hours of battery life.