Hospital grade audible alarm tamper-resistant duplex GFCI receptacle. Patented SafeLockā¢ protection for more safety - shuts off power to the receptacle if there's a ground fault, if the GFCI is miswired and even if the GFCI fails. This prevents the unsafe condition of power without protection. Tamper-resistant: Automatic shutter system prevents young children from inserting common objects such as hairpins or keys. The most durable GFCI available - exceeds UL943 voltage surge requirements; survives 100x the required UL 3kA/6kV voltage surge test cycles. Audible alarm notifies end user of tripped GFCI. Provides supplemental notification (along with trip indicator light - red LED). Alarm can be turned on/off. Side or internal screw-pressure-plate back wire termination speeds installation; takes #14 - #10 AWG stranded or solid, copper or copper clad conductors. Two back-wire holes per termination add wiring flexibility, eliminate pig tailing and save box space. Ground terminal back-wire clamp for fast installation. High-impact-resistant thermoplastic construction for superior strength and durability. 10kA short circuit rating.