For U-Line Contender 20A receptacles, tumbler switches, EDS/EFS series 4C control stations|Finish is epoxy powder coat for enhanced corrosion resistance|Large back box for ample wiring room|Ground screw installed in bodies for ground continuity|Corrosion-resistant stainless steel hex head captive screws hold covers to body|Factory sealed enclosure eliminates need for adding sealing fittings and compound at each conduit entrance|Accurately tapped, tapered hubs for tight rigid joints and ground continuity