Hubbell - HBL3765CLocking Devices, Twist Lock, Industrial, Male Insulgrip Plug, 50A 250V DC 600V AC, 3 Pole 4 Wire Grounding, Non NEMA, Screw Terminal, Nylon housing thermoplastic polyester interior, Black Super tough nylon housing offers better impact qualities Stainless steel shroud protects contacts and prevents mismating Heavy duty two piece external cord clamp provides maximum strain relief Box terminal with hex socket threaded slug, permits high clamping pressure