sensor to accurately track your riding rhythm in real time. Connect the rhythm sensor to the bicycle computer/indoor trainer via ANT+, and connect to the smart device application via Bluetooth. can easily fix the sensor on the bicycle crank and axle or shoes. rhythm sensor is waterproof, sweat-proof and dust-proof. Built-in replaceable CR2032 button battery, battery life up to 500 hours / wireless signal strength up to 20 feet. Easy to replace, use a coin to unscrew and replace the battery. Remember to remove the battery insulation sheet before installation. When the sensor is shaken, the LED flashes for 30 seconds to activate the sensor. IP67 waterproof, even in rainy days, you can ride with the bicycle sensor cadence and enjoy every day of riding in any weather. Rowing, Cycling, Running,Yoga,Climbing,Boxing,Gym exercise,etc Colour:Black Material:PC Package Contents: 1x Bicycle Speed Sensor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.