SunDing Bicycle Bike Speed Cadence Sensor Wireless Waterproof Bluetooth-compatible 4.0 Computer Speedmeter Cycling Parts Specification: Main material: ABS, plastic Product color: Black Product size: about 60x50x12mm/2.36*1.96*0.47in Net weight: About 40g Model: Bluetooth-compatible 4.0 2.4 Hz wireless transmission Battery life (estimated): 500 hours Battery: CR 1 x 2032 (Including) Wireless transmission distance: < 3M (9.9ft) Waterproof level: anti splash water level Working environment: - 10 ° C- 50 ° C Instruction: Stable cadence is the foundation of scientific riding and can help riders get a better energy output power ratio. When the pedaling frequency is too low, the unstable output power and muscle relaxation will waste energy. When the rider pedals too fast, the body will lose energy in order to overcome the resistance of the muscles. Reasonable cadence can also prevent sports injuries. Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-3cm measuring deviation due to manual measurement. Included: 1 x Wireless Speed Cadence Sensor