Strauss Bicycle Computer Odometer Speedometer | Waterproof LCD Display, Lightweight Multi-Function Cycling Accessory | Auto Sleep & Wake Up Mode, Speed Monitor | Easy Install & Read, (Red/Black) Multi functions with auto sleep and wake-up its records speed in mph/kmph, riding time, distance, scan, maintenance alert Distance speed tracking and clear large display as the wonderful percent wireless sign showed This bicycle speedometer is Shockproof and works great on rough roads as usual when riding Portable size, light weight, wide application this bike odometer is only for 1.8 x 1.8 inches (l x w) and 0.18 lb, which is easy to carry and save your space