Commercial Specification Grade. All nylon construction, high-strength brass alloy blades and connectors. Unitite single-screw wiring mechanism tightens all 3 wiring terminals at once for quick assembly. Clamptite cord grips automatically adjust to prevent strain on wiring terminals without damaging cord jacket or conductors. 2 nested self-tapping screws ease joining of shells. Rubber gasket seals off rear shell from dirt and particles. Convenient cord diameter and lead stripping gauges molded inside shell. Accepts round cord AWG No. 14-3 through 10-3. Ratings visible on face. Neoprene dust cover. UL (Underwriter's Laboratories) listed.