Panelboard Interior, Convertible, Main Lug, Circuit Breaker Series QHB, QOB, QOB-VH, Amps 225 A, Short Circuit Current Rating 100000 RMS Symmetrical, Number of Spaces 42, Voltage 120/208 to 240V AC, Phase Three, Bus Material Aluminum, Recommended Enclosure 1D700 for Main Breaker, 6B429 for Main Lug, Circuit Breaker Type Plug In Miniature, For Use With NQ Circuit Breakers, Height 33 in, Depth 5 3/4 in, Width 10 7/16 in, Main Circuit Breaker Adapter Kit 4HHA3, 4HHA4, Mfr. No. NQMB2KI These Square D NQ main lug panel interiors distribute power downstream from main breakers and are used with QO plug-in and QOB bolt-on circuit breakers to protect circuits from overcurrents. These interiors are used when all the circuit slots in the main breaker load center are full or when a remote panel is des.