This is my Gen II battery side cover with rounded contours to compliment the shape of the oil tank on the right side. This is a fiberglass piece made in black gelcoat. The surface from the mold is microscopically rough so I sand it with 2000 wet/dry and polish with 3M’s Finessette II so it looks like a factory part.
To install it remove the old battery cover (with skulls maybe) and the little triangular plate that hides electrics. Install my cover to the three mounts for the triangle cover. I provide three black flat head Allen screws that screw into that factory mounts. Over time these rubber mounts degrade. Hardware store and Harley rubber/metal mounts are too under sized to fit the frame holes snugly. Often I wrap the mounts with plastic electrical tape before I first install them-this helps a bit.