Expansion Plug, Thumb Nut, 3/8 In Price For: Each Material: Aluminum, Stainless Steel, Neoprene Rubber Max. Back Pressure: 24 ft. of Head Type: Thumb Nut For Use In: Low pressure seal in circular openings Nominal Size: 3/8" Min. Dia.: 0.356" Max. Diameter: 0.405" Country of Origin (subject to change): United States