Hubbell - HBL7410BLocking Devices, Twist Lock, Industrial, Single Flush Receptacle, 20A 3 Phase Wye 120 208V AC, 4 Pole 4 Wire Non Grounding, Non NEMA, Screw Terminal, Back wired, Black thermoset. High impact, abuse resistant nylon face Wire restraint recess for both back and side wiring, greatly reduces the possibility of loosening the terminal connection Face color coding by voltage facilitates locating and mating of proper devices All brass mounting and grounding