Energized receptacle contacts deeply recessed to reduce danger of accidental touching. Unique blade-type, brass contacts exert constant pressure along entire contact surface and provide superior electrical contact. Insulators provide superior dielectric and mechanical strength and lowest arc tracking. ECP plug fits any standard non-explosion proof receptacle (NEMA 5-20R, or 6-20R) as well as U-Line™ explosion proof receptacles. Choice of malleable iron receptacle and mounting box or aluminum receptacle and mounting box. Ground fault circuit interrupting cover and receptacle combinations available. U-Line™ EFSR-K receptacle covers are UL Classified when used with Killark™ SWB series mounting boxes. Intermateable with competitor's plugs of like configurations.