Electrical Apparatus-Namely, Conduit Boxes; Switch Housings; Entrance Fittings; Fixture Hangers; Motor Control Housings; Flexible Couplings; Junction Boxes, Plugs, and Receptacles; Explosion-Proof Switches; Explosion-Proof Control Stations; Control Centers (Switch Racks); Reducers; Close-Up Plugs; Sealing Fittings; Unions; Couplings and Connectors; Cast Outlet Boxes; Cord and Cable Connectors; and Parts Therefor