The Garmin Speed and Cadence Sensor 2 is an improved version of the earlier sensor units. With no magnets or other exposed parts to line up, these sensors are easy to install, maintain and move between bikes.
The Speed Sensor 2 attaches to the hub of either wheel and self-calibrates with your Edge® cycling computer or compatible Garmin device to give you accurate speed and distance at all times — even without a head unit.
The Cadence Sensor 2 fastens to any size crank arm and measures pedal strokes per minute so you can get the most out of your training.
Photo Credit: Garmin