Locking Devices, Twist-Lock®, Industrial, Single Flush Receptacle, 20A 3-Phase 480V AC, 3-Pole 4-Wire Grounding, NEMA L16-20R, Screw Terminal, Nylon face, Back and side wire, Black.
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 system provides a lower resistance ground path and greater resistance to corrosion than steel mounting systems