Seal extra pushbutton holes, conduit openings and knockout openings against dust, dirt, oil and water with Hol-Sealers hole seals . Seals will cover any size or shape of hole from .19-in. diameter to maximum diameter shown in table. Can be used on enclosure walls up to .31-in. (8-mm) thick. Maintains enclosures Type rating 3R, 4, 4X (Stainless Steel version only) 12, and 13 when installed in an nVent HOFFMAN enclosure.