US Patent 7610937 Self-sealing regulator fill port protective/dust cover

A self-sealing protective/dust cover for application to a magnetically attractable filling port includes a sleeve defined by a closed wall and closed at one end by an end face. The closed wall defines an open central region and the end face is contiguous with the closed wall. A magnet provide magnetic attraction between the protective/dust cover and the filling port to maintain the protective/dust cover on the filling port.