Warm Tips:The attached base can firmly lock this computer onto the slot and prevent falls and drops in bumpy road, Install the sensor on the front brake,magnet is installed on spoke, 4mm close to the sensor.Battery can be replaced, easy to open the battery case with a coin to help, coin not included. Why Choose Us:It is made of premium quality ABS material which makes it very safe and durable.Meanwhile, this odometer is waterproof so it is very convenient for you to use it in rainy days. Furthermore, due to its special backlight feature, you can use it both at day and night.Also, it is very easy to install and is suitable for most of the bicycle models. 27 in 1 FUNCTIONS:Current Speed, Average Speed, Odometer, Trip Distance, Maximum Speed, Total trip down, Total Riding Time, Stopwatch, Over Speed Reminder, 12/24 hour clock, Temperature Display, KM/MPH Selection, LCD Backlight, plus/- Speed Comparator, Trip Distance Up, Trip Distance Down, Trip Time Up, Trip Time Down, Maintenance Alert, Low Battery Indicator, Auto on/off, Setting Type Circumference, Freeze Frame Memory, Setting the Latest Value Odometer, Care reminder, Comparator, Riding Time. EASY TO INSTALL & WIDE APPLICATION:Our bike computer only takes a few minutes to install. customizable to most common tire sizes for accurate stats tracking. small size, lightweight and wireless design make it suitable for most types of bicycles: road bicycles, mountain bikes, folding bicycles, common bicycles, pit bikes, etc. WATERPROOF:Small size, lightweight, easy to transport and install. The waterproof design makes it more comfortable and durable even, You can still enjoy your cycling travel on a rainy day. The merchant warrants that their products comply with all applicable laws, and are offered only if they comply with Joom's policies and EU Product Safety and Compliance laws.