Single phase, 3-wire, solid neutral, 2 spaces and 4 circuits maximum 1-pole, 1 QP breaker maximum 2-pole, 120/240 VAC. 10,000 AIR. With closure plates, HS style hubs sold separately, uses ECHA075 (694.3559) Hub. One piece plated aluminum bus bar. 100% circuit breaker twist outs. Will not accommodate 2-pole GFCI or circuit breaker with shunt trip. Positive load side circuit breaker hook rail. When used as service equipment, any unused neutral position may be used for equipment grounding. Rotate entire device 180 deg for bottom feed. Gray enamel finish. CSA and UL listed, complies fully with NEC and UL requirements for Class CTL. 5 in x 8 in x 4-1/4 in.