Application: Closure of Unused Box Outlets | Brand Name: Sigma Electric | Color: Gray | Material: Die Cast Zinc | Packaging Type: Bagged | Shape: Round | UL Listed: Yes | Width: 3/4 in. Sigma's weatherproof closure plugs help keep moisture from the electrical wiring by closing unused holes in weatherproof boxes, extension rings or covers. | For closure of 3/4-in threaded knockouts in a weatherproof box or cover | Includes four 3/4" closure plugs | Zinc die-cast construction