This Rear Fender Filler from Show Chrome Accessories closes the gaps that the rear fender misses on the 2018 and newer GL1800. It reduces flying road debris missed by the fender, reducing dust and dirt on your bike or trailer, keeping them cleaner. The flat surface created by this rear fender filler allows mounting of accessories and lights to a flat surface. Does not interfere with Show Chrome Accessories 52-921 Trailer Hitch.