3/8” Recessed type head plugs for a properly sized 3/8” hole in material up to .080” thick. Button Plugs have recessed type heads and can be used for plugging holes in equipment made of sheet metal such as auto bodies, tanks, refrigeration units, etc. These plugs can be snapped into holes easily and are held in place by a bead until deliberately removed. Material: Low-density polyethylene Service Temperature: -94 - 175° F (-70 - 79° C) Color: Black.