Square D QOU380 Qo Miniature Circuit Breaker. Square D QO Miniature Circuit Breaker, Type QOU Standard Unit Mount, 240 VAC, 80 A, 50/60 Hz Frequency, 10 kA Interrupt, Thermal/Magnetic Trip, 3 Pole, 3 ph, Toggle Actuator, Box Lug Connection, 12 to 2/0 AWG Wire, DIN Rail/Flush Mounting, 104 deg F, 2.95 in L x 2.25 in W x 4.45 in H Dimensions, Black. Additional Description: SQD -QOU380 MINIATURE CIRCUIT BREAKER 240V 80A. Catalog Description: Mini circuit breaker, QOU, 80A, 3 pole, 240 VAC, 10kA.