ILSCO Power Distribution Block, Mechanical connection, Dual Rated, Aluminum material, Tin plated connector,mounting bolt/stud size 1/4 in, mounting hole spacing 4.75 in., UL 1059 Recognized, C22.2 No. 65-03, Copper/Aluminum Primary Conductor 500 kcmil - 4 Str, Copper/Aluminum Secondary Conductor 10 Sol - 14 Sol and 4 Str - 14 Str, 14 conductors, Drive Type Main 3/8 Internal Hex, Drive Type Tap Slotted, rated for 600 V, primary color Black, 3 poles, 2 ports per pole primary, 12 ports per pole secondary,