Hubbell - CS8164CLocking Devices, Twist Lock, Industrial, Female Connector Body, 50A 3 Phase Delta 480V AC, 3 Pole 4 Wire Grounding, Non NEMA, Screw Terminal, Black and White Box terminal with hex socket threaded slug, permits high clamping pressure on conductors without damaging strands Heavy duty two piece external cord clamp provides maximum strain relief Thermoplastic polyester interior provides heat resistance and impact strength Oversized contacts minimize