Manufactured by Top Secret PDR 1/4” Locking plug for use in 1/4” holes in sheet metal these plugs snap into a cleanly drilled hole and give it a professional looking finish. These 1/4” plugs are made for use in Sheet metal commonly referred to as a knock out plug. These are also used in Paint-less dent removal to fill 1/4” holes. The can also be called locking plugs as when they are put in the sheet metal they snap into place. dome plugs are finishing plugs for unneeded or unused holes in chassis or other surfaces. Convex design tapers to a thin edge for a seamless finish Matte finish head offers a professional and finished appearance Easy installation Plugs lock firmly into surfaces Material: Nylon 6 Color: Black