Monitor your speed and cadence as you ride with these easy-to-install wireless sensors. 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.