Rubber bumpers are designed for through hole installation. Designed to fit snugly into your opening and not let air, water, etc. pass through. Can also be used as feet. For Heyco Adhesive-Backed Bumpers, click here. Part Description Key: RGB X-Y-Z where X = Mounting Hole Diameter (inches), Y = Base Diameter (inches), and Z/32 = Base Height (inches).