Hubbell TWIST-LOCK cable plugs and connectors are made of white nylon locking blade insert, black housing and 2 pieces screw cable clamp. Flanged inlet and outlet are made of white one-piece nylon. Box single/duplex receptacle are made of black or orange (isolated) thermoplastic. Full line of accessories like stainless steel and weatherproof cover plate. They follow NEMA and NON-NEMA lock coding version 1-2-3-4 pole, 20-30-50 amp, 125-250-277-347-480-600 volts.