[Bluetooth and ANT+Dual Atom] Use V4 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. [Wide compatibility] The speed sensor is compatible with most mainstream iOS and Android fitness applications: Zwit, TrainerRoad, Rouvy, Cyclemeter, Openrider, , RideWithGPS, , etc. [ and easy to install] You can easily fix the sensor on the bicycle crank and axle or shoes. [Quality] V4 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. [Practicability] When the sensor is shaken, the LED flashes for to activate the sensor. IP67 waterproof, even in , you can ride with the bicycle sensor and enjoy every day of riding in any weather. , Cycling, Running,Yoga,Climbing,Boxing,Gym exercise,etc colour: black Material: plastic Size: 38.5x38x12mm Package Contents: 1 x speed sensor Only the above package content, other products are not included. Note: Light 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.