round or cylindrical shape made of metal, rubber, plastic, or wood a hole in the center a handle or knob for gripping a knob, lever, or switch for releasing or locking the stopper in place a rubber or metal gasket for creating a tight seal
stopper which has round or cylindrical shape stopper which has made of metal, rubber, plastic, or wood stopper which is a hole in the center stopper which is a handle or knob for gripping stopper which is a knob, lever, or switch for releasing or locking the stopper in place stopper which is a rubber or metal gasket for creating a tight seal