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-circuits 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. On top of that, all QO circuit breakers are equipped with the exclusive Visit-Trip indicator. When a QO Visit-Trip circuit breaker trips, the handle snaps to a midpoint position between inch OFF inch and ON inch and a highly visible, red indicator easily identifies the tripped breaker. This enables you to easily distinguish which breaker has tripped in a load center that may contain up to 42 different circuit breakers. QO circuit breakers have features no other manufacturer can offer. They come in many different sizes and can meet the needs of virtually every function in your home or business.