Square D QOB220 Qo Miniature Circuit Breaker Brand: Square D. Part Number: QOB220. Square D QO Miniature Circuit Breaker, Standard, 120/240 VAC, 20 A, 50/60 Hz, 10 kA Interrupt, Thermal/Magnetic Trip, 2 Pole, 1 ph, Pressure Plate, 14 to 8 AWG Wire, Bolt-On Mount, 40 deg C, 2.91 in L x 1.5 in W x 3 in H. Additional Description: SQD -QOB220 MINIATURE CIRCUIT BREAKER 120/240V 20A. Catalog Description: Mini circuit breaker, QO, 20A, 2 pole, 120/240VAC, 10kA, bolt on..