Shell and extra pole grounding style 2|Energized receptacle contacts deeply recessed to reduce danger of accidental touching|Spring door keeps dust out of receptacle when plug is not in use, screw cap also supplied|Brass contacts exert constant pressure along entire contact surface and provide superior electrical contact|Contacts have beryllium copper wire springs, plug mechanical cable clamps prevent strain on cables they meet or exceed UL strain relief pull out requirements|Neoprene bushing compressed by cable collar prevents entrance of water|1-1/2 NPT tapped conduit openings one top to bottom|Interlocked disconnect switch provides safe connect and disconnect operation|Fiberglass reinforced polyester insulating blocks|Insulators provide superior dielectric and mechanical strength and lowest arc tracking