Single phase, 3 wire, 10 spaces and 20 circuits, 2 single pole breakers and 1 double pole breaker, 120/040 Volts ac. 22,000 interrupting capacity. Use for older home renovation projects where the distance between the studs are narrower then current construction practices. One-piece bus bar construction designed for use only with circuit breakers. Simple dead front adjustment after trim is installed. Positive load side circuit breaker hook rails. U.L. Listed. Ten year limited warranty.