Used to provide additional capacity needed for NEC box fill requirements. Die cast aluminum construction. Installation hardware gasket and 1/2 in closure plugs included. Ground screw is provided. Internal threads and hubs comply with NEMA requirements. Hubsaccept all threaded 1/2 in fittings and threaded conduit. 5-1/4 in Length x 3-1/2 in Width x 1-1/2 in Depth. UL 514-A listed, File E 195978 CSA C22.2 no. 18 NEMA 3R rated.