Protects you from electrical shock due to hazardous leakage levels from appliances and tools, exposure to moistuer while operating electrical appliances, and frayed or damaged wire. New Labor saving feature; terminal screws are backed up and ready to wire. Screw pressure plate back wire termination takes #12 or #14 AWG stranded, or copper, or copper clad construction. Extra-long mounting straps. Unbreakable face. LED trip indicator. Easy access ground screw. Side and back wire, wall plate included. Plus Self Testing.