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+ duel band technology allows you to connect and display data on both smartphone and bike computers. - 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