This is a general purpose mechanical speedometer for a bicycle or tricycle. It is a high quality cycling equipment made of durable aluminum alloy. Can guarantee a long service life. The bicycle speedometer is a purely mechanical bicycle computer, not only with good quality, but also with accurate data. The high-resolution backlit display is easy to read even in bright sunlight or darkness. Ensure safe driving. The mechanical bike odometer features a new upgraded program and optimized chip material to provide you with more reliable speed and time data every time. output. This bike computer accessory is complete and easy to install, you can easily do it yourself. A mechanical odometer is the basic tool you should need when riding a bike, and you will find it useful. This bike computer is only suitable for 26/27.5/28 bikes /29 inches. Fitment Requirements: Requires quick release lever or large front wheel clearance to fit.