Busway Plug In Unit, Amps 250 A, Voltage 600V AC, Number of Poles 3, 3 Phase, 4 Wire with Ground, Enclosure Rating NEMA 1, For Use With SE Square D I-Line and I-Line II Busway, Fusible No, Breaker Type H,J, Height 8 1/2 in, Width 21 11/16 in, Depth 9 1/8 in, Standards CSA C22.2 No 27, UL Listed file E22182