B-Line Post Base, Rectangular U Type, 2 Channels, Flush to Side Channel Position, 3-1/2 in Base Height, 8 Channel Mounting Holes, 8 in L x 3 in W x 1/4 in THK Pad, 2 Pad Mounting Holes, For Use With: 1-5/8 x 1-5/8 in B22A, B22B and B22C Series Side by Side Channel, Steel, Zinc Plated