The Wahoo RPM Speed and Cadence Sensors Combo Pack are all you need for cycling data, all together at once! The Wahoo RPM Speed and Cadence sensors are both a sleek, wireless, and magnet-less solution. Each mounts easily to your bike and the Bluetooth Smart and ANT+ dual band technology allows you to connect and display data on both smartphone and bike computers. Wahoo RPM Speed and Cadence Sensors Combo Pack Features Dual Band Technology Wireless Connection Magnetless Sleek, Lightweight Design Speed Measurement Hub Mount Visible Connection Replaceable Battery Universal Fit Wahoo RPM Speed and Cadence Sensors Combo Pack Specifications Physical Dimensions (LxWxH): 1.25 x.75 x 1 Weight: 7 grams (without mount) Battery: CR2032 Battery Life: Up to 12 months Water Rating: IPX7 (waterproof up to 5 ft) Wireless Signal Strength Up to 10 feet *Note: Speed Sensor is NOT compatible with spin bikes