The Square D QO tandem circuit breakers are a perfect low cost solution if you need to add an extra circuit when your main panel is full. Adding tandem breakers double the number of circuits in a panel. When it comes to electrical protection, fast response is critical and QO circuit breakers can trip faster than the blink of an eye. The exclusive QO Visi-Trip instantly identifies a tripped circuit breaker with a red indicator window. The Visi-Trip reduces the number of call backs, as well as the chance that other circuits will be turned off accidentally. This breaker will work only in Square D branded residential panels. Typical applications for a single pole 15 Amp breaker include lighting and receptacle circuits in a home and requiring a wire size of 14-2.