Park Zone Pz-1600 Precision Parking Aid Park Zone provides a solution for parking in crowded garages or for people who have difficulty with depth perception. The product installs with just 4 supplied screws. You park your vehicle in the desired location inside the garage, press the button on the top of the unit, and the system is ready. Park Zone will tell you when your vehicle is about 8 ft. from the wall by illuminating a yellow light. When you reach the desired distance, the red light visually indicates that it's time to stop. Park zone parking aid Ultrasonic technology provides wide-range sensing for precise parking Red and yellow lights for easy guidance Up to 16 ft. sensing range 4 screws included NWT