Simply mount the laser beam module on a selected location on the ceiling. The location will depend on where you want the laser beam to shine on your car. As you pull your car into the garage the system detects you are approaching and shines a bright vertical laser beam onto your vehicle. When the laser beam reaches the spot on your car that you have pre-selected as the target spot then you know you have successfully parked your car. So if youe pulling in too far, choose a spot on the dash and stop when the laser points to that location. The Laser Guided Parking System requires only a screwdriver to install, and runs on AC power or a 9-volt battery. One more ding, it costs much less than a new paint job for your car.