Pass & Seymour Hospital Grade Tamper-Resistant Weather-Resistant Self-Test GFCI receptacles with SafeLock® Protection conduct an automatice test every three seconds, ensuring they're always ready to protect. If the device fails the test, the indicator light flashes to signal that the GFCI should be rerplaced. It also has our proven SafeLock Protection feature: if critical components are damaged and protection is lost, power to the receptacle is disconnected.For detailed GFCI receptacle information, visit our GFCI Headquarters. Features: Patented SafeLock® Protection -- if critical components are damaged and ground-fault protection is lost, power to the receptacle is disconnected.; The indicator light flashes if the device fails the self-test, signalling that the GFCI should be replaced.; Prevents line-load reversal miswire: no power to the face or downstream receptacles if wired incorrectly.; Tamper-resistant automatic shutter system prevents young children from inserting common household objects.; Nickel-plated steel terminal screws for side wire or internal pressure plate for back wire with #14 - #10 AWG stranded or slide, copper or copper-clad conductors.; Two back-wire holes per termination add wiring flexibility, eliminating pigtailing and saving box space.; Captive zinc-plated steel mounting screws make for easier installation.; The most durable GFCI available: Exceeds UL943 voltage surge requirements.; Auto-ground clip assures a positive ground to metal box.; UV-resistant nylon construction for superior strength and durability.; Ground terminal clamp allows for fast installation.