"LCD display lets you easily read your stats Small size, light weight, wireless and waterproof, making it convenient and durable. It measures speed, distance, travel time. The serious cyclist or fitness enthusiast can track their time in the saddle and distance traveled LCD backlight to distinguish day and night. Easy to install Cordless and waterproof design makes it more convenient and durable. Please note that the slight clicking sound of the device is a normal phenomenon, it is the result of the design of wireless automatic function. The screen will enter sleep mode with LCD screen if no signal will be input in 300 seconds. Memory function. This bike computer wakes up automatically when you shake it or any signal is input or any button is pressed. The auto-wake function of this wireless bike computer: ball switch built-in, make the watch body vibrate after sleep, and automatically turn on once the ball switch detects vibration Material: Engineering Plastic ABS Electronic Components Display: LCD Size: 4.6*4.6*1.9cm Weight: about 90G Power supply: 1 CR2032 button battery in the measuring head; 1 x 12V 23A battery in the transmitter，This product does not include batteries and must be purchased separately Configuration: head*1, wireless rotating base*1, magnet*1, cable tie* 4, rubber ring*1, manual*1, wireless transmitter*1 Color: Black Backlight: Green/White Scope of delivery: 1 piece luckymeet "Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be some certain color difference, the actual object received shall prevail.