The Steering Wheel Alarm will protect your vehicle from unauthorized entry with 3 theft-deterring features: alternating warning LED, a 125 dB alarm, and a flashing strobe light. No installation is required; the alarm simply fits onto the steering wheel of any car. Turn it off and on by the included remote (256 possible code combinations for added safety). The highly-visible, alternating LED acts as a deterrent. If the vehicle is disturbed the vibration / movement sensor (which has high and low sensitivity settings) will activate the alarm and strobe for 35 seconds and then reset. The remote requires one (1) 12V alkaline battery (included), the alarm requires two (2) 9V alkaline batteries that are not included. The alarm measures 5 x 4 x 2 inches.