The compact speed sensor 2 easily mounts to your bike, sending live speed, distance and cadence data to your favorite training app or display using ANT ® connectivity and BLUETOOTH® Low Energy technology. After your ride, the speed sensor 2 can sync your speed and distance data to the Garmin Connect™ online community. -Compact sensors record speed and distance when training outdoors and indoors -Send live speed and distance data to compatible training apps or displays using ANT ® connectivity and BLUETOOTH® Low Energy technology -Sync your speed and distance data with the Garmin Connect™ online community after your ride -In stand-alone mode, the speed sensor 2 can record speed and distance data without a head unit or phone -Battery life: up to 1 year