The Square D by Schneider Electric QO 20 Amp Single-Pole Combination Arc-Fault Circuit Interrupting (CAFCI) Circuit Breaker is for use to help protect your wires from arcing faults and is intended for overload and short-circuit protection of your electrical system. Now standard in all Square D brand CAFCI circuit breakers, Time-Saver Diagnostics provide advanced trip indication technology, helping identify the type of fault that has occurred faster. Time-Saver Diagnostics helps take away the guess work and provides diagnostic assistance by identifying the type of fault that last occurred. It saves money by reducing troubleshooting time, simple to use, accurate and reliable. All QO circuit breakers have the exclusive Visi-Trip indicator that, when tripped, the handle snaps to a position between "OFF" and "ON" and a hi viz, red indicator identifies the breaker.