Vehicle Radar 4 sensor backup safety system. Brand New. This is about a $600 dealer option if purchased with a new vehicle. Install your own and save! Kit comes with the correct size drill bit for the 4 sensors. The Unit Turns Itself "ON" Automatically, and then beeps faster and faster, and then emits a steady beep as you get closest to an object behind you, while you are backing up. Great News - No more backing up into parked cars, light poles, etc.... This unit pays for itself by saving damage to your vehicle from the very first "accident" that you would have backed into without this very practical unit installed. Unit turns itself on automatically each time you place your vehicle in "reverse". I can demonstrate one of these units for you that I have on my car. If you live too far away and would like one of these shipped to you via U.S. Mail, for just $8 more, I can ship it to you.