Waterproof LCD Digital Wireless Bicycle Bike Cycle Computer Auto sleep and wake up: Built-in vibrating ball switch, if shaking the computer unit while it is on sleeping mode, ball switch will sense vibration and then automatic starup. Multi function, Offer accurate riding data for your riding life, such as Current/Average/Max speed, Elapsed time, Trip/Total Distance and Clock, etc. Backlight: It will turn on when you press any button during PM:1900 and AM:700, offer clear viewing at night; Waterproof: Riding in a rainy day is also ok, but don't put in the rainstorm or soak in water for a long time. Suitable for all types of bicycles: road cycling, mountain biking, folding bike, common bicycle; Suitble wheels size: Spokes diameter range is 0-4.5 mm, wheels circumference range is 0mm9999mm