Protects children: patented shutter system helps prevent improper insertion of foreign objects Meets 2008 national electrical code tamper-resistant requirements Safe lock protection: if critical components are damaged and ground fault protection is lost, power to receptacle is disconnected Prevents line-load reversal mis-wire: no power to the face or downstream receptacles if wired incorrectly Two back wire holes per terminal Ground screw has a back wire clamp for easy installation Trip indicator light (Red LED) Foul listed (Federal specification WC596)