The bike wireless computer odometer is small, lightweight and waterproof for long-lasting durability. It measures speed, distance, ride time flawlessly, which is what serious cyclists need. This wireless multifunction bicycle speedometer is easy to install. It accurately measures your work rate and progress. Instructions included will guide you through the following functions Features Auto Wake Function - Automatically wakes up from sleep mode after sensing bike vibration. Bright LCD display for easy viewing of riding statistics Multifunction - Small size, light weight, wireless, waterproof design makes it convenient and durable. This cycling computer measures speed, distance and ride time. Just what any serious cyclist or fitness fanatic needs for stat tracking EASY TO INSTALL AND USE - Installation is simple and only takes a few minutes. Easy-to-navigate interface with just two buttons to access all measurements. Customizable to most common tire sizes between 20" - 27" for accurate stat tracking Compatibility - Road bikes, mountain bikes, folding bikes and other bikes are compatible with this bike computer. This cycle computer may not be compatible with certain pedelecs or small wheel diameter bicycles. If the computer monitor, sensors and magnets can be mounted within the specified distance, the device should be fully compatible. Easy steps to setup: 1 - Install the battery The sensor and computer both need batteries 2 - Attach the bracket to the handlebar 3 - Attach the sensor to the fork 4 - Attach the The magnet is attached to the spoke so that its flat face faces the sensor 5 - Mount the bike computer to the bracket