Description 100% brand new, high quality Product: Speed sensor Model: gemini210 Size: 8.85x29.8x38.3mm Waterproof: ip54 Sensor: Geomagnetic sensor Battery: 2032 button battery Wireless interface: Bluetooth/ant+ Battery life: 400 hours How to use 1. When using speed and rhythm together, you need to buy two 2. In speed mode, you need to set the wheel size to use the app Then the speed can be displayed accurately 3. The first time the equipment is used, the insulation paper needs to be removed Make sure battery + up 4. Install the battery to switch the mode speed model to the rhythm model Quality first, provide the best service. Customers are our friends. Notes: 1. Please allow slight chromatic aberration in the photo 2. Due to manual measurement, the size may be deviated Package Included: 1pcs speed sensor (with a battery)