SmartlockPro® Self-test GFCI tamper resistant receptacle provides continuous ground fault protection detects and trips on actual ground fault even when self-test is being conducted. NEMA 5-20R, back and side wired. Duplex with LED indicator (with self-grounding clip). Patented bridge contact provides individual sets of contacts for GFCI receptacle face and downstream receptacles, no power will be delivered to receptacle face if improperly wired (line-load reversed). Trip threshold meets or exceeds UL requirements for tripping time. Improved immunity to high frequency noise reduces nuisance tripping. Advanced electronics provides superior resistance to electrical surges and over-voltages. Patented lockout action prevents reset if GFCI is damaged and cannot respond to a ground fault. Status indicator light provides simple, intuitive feedback on power and protection status as well as indication of line/load reversal. Silver alloy contacts. Impact-resistant thermoplastic cover and body.