These are a 120VAC, 230VAC single phase and 120/208VAC three phase, 70" long power distribution strips that is 1 "U" (1 3/4") high and 2.50" deep. The 500 series PDU strips have forty-two (42) NEMA 5-20R or 6-20R receptacles on the panel. This series comes standard with circuit breakers. The 500 series comes in various voltage & current ratings depending on model.