Square D by Schneider Electric QO 20 amp 1-pole Dual Function Circuit Breakers is a space and labor saving device, engineered to meet prevailing NEC requirements. This device combine two critical technologies, Combination Arc Fault protection and Ground Fault protection (class A), in a single, easy-to-install device. The NEC now requires both Combination Arc Fault and Ground Fault protection on all 1-Pole, 15 amp and 20 amp kitchen and laundry circuits. Prior to the release of this new device, a contractor or homeowner's only choice would have been to use a Combination Arc Fault circuit breaker in conjunction with an expensive, bulky Ground Fault receptacle. The new Dual Function circuit breakers help reduce cost and eliminate the hassle of using two separate devices to provide this essential protection. It's a win for contractors and homeowners alike. Like all Square D CAFI Circuit Breakers, it is integrated with time saver Diagnostics, a unique feature that provides additional circuit information and minimizes troubleshooting at the touch of a button.