Schneider Electric Usa Inc 1-Pole Air Tandem Circuit Breaker 20A 120/240V ac 10,000Square D introduces this 20 amp breaker that is sure to be of great use to you. It is a single pole breaker that offers two poles in the space of 1. This electric breaker features a Qwik Open and Visi trip indicator that helps to identify a tripped breaker quickly. Square D breaker trips thermally (in an overload situation) or magnetically (under a short circuit situation). The replacement breaker is for use in old style, non class CTL QO load centers