The Square D QO tandem (Space Saver) 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 QO branded residential panels. Typical application for a single pole 20 Amp breaker include kitchen counter outlets circuits with GFCI protection and requiring a wire size of 12-2.