This Car Reverse Backup Radar System consists of 4 Ultrasonic sensors, digital control box, and av in / out. It accept backup video from rear view camera, then output combined video with distance data. It makes the job of parking any vehicle much easier. It auto detects the distance between the car and back obstruction through the sensors installed at the rear bumper of the car. It helps to avoid the dangerous and costly collisions that occur so easily behind the wheel. Other Features: - Visual distance data shows in output video- With a drill head, convenient to drill hole on the bumper of the car- Be beneficial to prevent dangerous and costly collisions- Central AV controller box for easy connection- High quality, easy installation and operation Specification Rate voltage: 12V DC Rate operating range: 10.5V - 16V DC Rate current: 100mA - 300mA Detecting distance: 0.3 - 2.0Ultrasonic frequency: 40KHz Control module working temperature: -30 - 80 celsius degree Display working temperature: -20 - 70 celsius degree Indicator size: 44x17mm (D x H) Sensor size: 19x25 (H x D) Main control box size: 90x60x23cm Main control box weight: 63gItems Included1 * Main Control Box2 * AV Cables (In & Out)4 * Parking Sensors with 2.5M Line1 * Hole Saw1 * Power Cable2 * Double Side Sticker1 * User Manual.