Lezyne Pro Speed SensorA high-quality speed sensor, the Lezyne Pro Speed Sensor which connects to multiple devices a with high-tech dual Bluetooth system. The sensor is made with a Translucent Composite Matrix and is incredibly lightweight and compact. Easy to install the sensor can be attached to most hub types and it comes with a magnet-free installation.SpecificationsWeight: 11gDimensions: 37mm x 33mm x 13mmFeaturesSuper compactLightweightMagnet-free installationTranslucent Composite Matrix constructionLED indicatorMounts to most hubsHigh-tech dual Bluetooth systemPowered by a replaceable CR2032Buy Lezyne Cycle GPS from Chain Reaction Cycles, the World's Largest Online Bike Store.