Need for speed
Monitor your speed as you ride with the wireless Garmin Speed Sensor 2. With no magnets or other exposed parts to line up, it's easy to install, maintain and move between bikes.
Speed sensor 2 attaches to the hub of either wheel. You can set up wheel size in the Garmin Connect app or self-calibrate with an ANT+/Bluetooth compatible Garmin device. Once set up, you’ll get accurate speed and distance at all times — even without a head unit.
Product details
Speed sensor attaches to the wheel-hub to give accurate speed and distance
Transmits data via ANT+ and Bluetooth
Syncs with Garmin Connect app, other training apps, and ANT+/Bluetooth compatible devices

Battery : CR2032
Clamp : Universal
Component type : Speed/cadence sensor
Weight : 83g