The GE 20 amp Single Pole Ground Fault Circuit Breaker with self-test has a tin plated copper stab to create a reliable, permanent and corrosion resistant connection. It is used as a substitute to GFCI wall outlets allowing the customer to know exactly where to go (back to electrical panel) in the event of a tripped circuit. No more searching for the correct wall outlet to reset. The self-test functionality is a UL requirement on all GFCI devices commencing in June 2015. This variant of the GFCI ensures its ground circuitry is functioning properly by automatically running diagnostic testing on a periodic basis. Should a problem be detected, the circuit breaker will trip and will need to be replaced.