The Launch 'N Load Trailer Guidance System makes trailer backing quick and easy by fixing 3 of the most difficult aspects of trailering. First, it gives you a reliable visual-tracking guide when backing an empty trailer down the boat ramp. Second, it signals that your boat is clear of the trailer when unloading. And lastly, it assists in locating the trailer's centerline when loading. (Signal arm automatically folds down when the boat is loaded onto your trailer.)