QO and QOB one, two and three pole thermal magnetic circuit breakers provide overcurrent protection and switching on ac and dc systems. These circuit breakers have an over center, trip free toggle mechanism with quick make, quick break action and positive handle indication. They also have VisiTrip trip indication, which provides a visual indication that the circuit breaker has tripped and interrupted the circuit. This 2 pole QO main breaker is rated at 90A at 120/240VAC. This unit provides 22kA breaking capacity and bolt on mounting. A full line of features and factory installed accessories are also available such as shunt trips, auxiliary switches and alarm switches. A full line of accessories are available. The box lug connectors will accept one 4 AWG to 2/0 copper or aluminum wire. This circuit breaker has a height of 5.09 inches, a width of 3.47 inches and a depth of 5.00 inches. A full line of accessories are available. The box lug connectors will accept one 4 AWG to 2/0 copper or aluminum wire. This circuit breaker has a height of 5.09 inches, a width of 3.47 inches and a depth of 5.00 inches. This QO main circuit breakers is UL Listed and are CSA certified.