Features1Bluetooth and ANT+ Multi Protocol: Supports connectivity with bike computers, bike apps, fitness devices and smartwatches to collect speed or rhythm data via Bluetooth or ANT+. 2Dual Mode Sensor: Easily switch speed and rhythm by switching to different positions. Activate the indicator light to tell you the health of your battery when you wake up. Blue means it's configured as a speed sensor, green for a rhythm sensor, and red for low battery. 3Easy Installation: Easy connection to the bike crank and hub using the included elastic and rubber base. Maintenance and moving between bikes. Suitable for road bikes or indoor trainers, compatible for small G+, for feng, for WAHOO, for Garmin sports watches, cycling platforms and other equipment. 4Mini Design and Long Term Continuity: The size are only 40x30x10mm and the weight is only 9 grams. Does not affect the appearance of the bike, increase the burden of the bike. When not exercising, it goes into sleep mode. 400 hours of use and 400 days of standby time 5IP67 Water Resistance: The rhythm sensor has an IP67 water resistance rating, allowing you to ride freely without being hindered by the weather. (Do not immerse in water)SpecificationItem Type:BicycleSpeedCadenceSensorWeight: 36g/1.27ozMaterial: Plastic, electronic components, rubberBattery Type: CR2032 button battery (shipped with built in battery)Battery Capacity: 150mahNumber of Batteries: 1Size: 40 x 30 x 10mm/1.57 x 1.18 x 0.39inPackage List1 xBicycleSpeedCadenceSensor4 x Accessories1 x Instructions