Square D, QO340, Miniature Circuit Breaker, Standard, 240 V AC, 40 A, 50/60 Hz Frequency, 10 kA Interrupt, QO Frame, Thermal Magnetic Trip, 3 Pole, 3 ph, Box Lug Connection, 8 to 2 AWG Wire, Plug-On Mounting, 40 deg C, 3 in H x 2.25 in W x 2.91 in D Dimensions