Wireless and waterproof: the waterproof bicycle compter is easy to install and adjust, which makes the speedometer more comfortable and no need to worry about rainy days. Backlight: the wireless bicycle speedometer is designed with the green backlight, LCD digital display. When any button is pressed between 18: 00 and 06: 00, the backlight will turn on automatically. Please note that the slight creaking of the device is normal, depending on the design of the wireless automatic function. And our wireless bicycle computer is rotated either in day or night mode to guarantee you can easily read your stats at any time Portable and multifunctional: The bicycle computer is not only small size and light weight, but also many functions can support your needs. This bicycle watch can measure speed, distance and riding time. What does a serious cyclist or bodybuilder need to know to track statistics? Sleep mode and auto wake up: The speed meter automatically switches to sleep mode when it is free for over 5 seconds, and wakes up when any data is re-entered or a button is pressed. It is beneficial to save energy of the battery. Suitable for all bicycles: the bicycle clock meter is suitable for all bicycles. It is not limited to your wheel size, but please follow the instructions for installation. The distance between sensor and wireless bicycle computer should not exceed 50 cm, sensor and magnet no more than 3 mm, or it does not work. Product description Material: ABS Size: 4.6 * 4.6*4.6*1.8cm Black display : LCD screen Backlight: green/white Features: wireless automatic wake-up Power supply: there is a CR2032 button battery on the measuring head; 1 12V 23A Number of transmitter batteries: 1 Package: 1 * bicycle odometer