The Rostra 250-1594 is a Obstacle Sensing System (ROSS) detects objects that you can't. Using the latest microwave motion sensing technology, the ROSS alerts you to obstacles as far away as 12 feet behind or next to the rear end of the vehicle.
Features:
Alerts Driver with a Three-Color Visual LED and an Audible Beeping Tone
Works in Poor Weather Conditions
State of the art Microwave Motion Sensing Technology