The Square D QO 40 Amp 1-1/2 in. Double-Pole Circuit Breaker is compatible with QO load centers, QO enclosures and NQOD panel boards. The breaker features a Visi-Trip indicator to easily identify a tripped circuit in the load center. This circuit breaker has a maximum load of 240-Volt with a 10,000 AIR and uses a thermal-magnetic tripping mechanism.