Knockouts, pushbutton holes, and conduit openings can be sealed against dust, dirt, oil, and water with Austin Hole Seals. Hole Seals are fabricated from 14 guage steel with an ANSI 61 gray polyester powder coating of from 14 gauge Type 304 stainless steel. All Hole Seals are constructed with a neoprene oil resistant gasket, stainless steel stud and stainless steel wing nut.