1" Rubber Drill Hole Plugs with Compression Stem Various Pack Sizes 1" (other sizes also available) For additional Sizes Click HERE The dimensions listed for each plug is the hole size. The top dimension is larger in diameter than hole plug Stem bumpers are typically used as hole plugs or insertable bumpers for vibration and noise reduction. Thickness of Head: 1/16 -1/8” Silicone Rubber Durometer Hardness: 60