C.E. SmithDouble U-Bolt Bolster Bracket – 8-3/4″Model:10190G40Mounting bunk boards using double U-bolt bolster brackets provides the most rigid bolt-on bracket mounting possible. Made from heavy 7 ga galvanized steel, these brackets are 4 wide with slots that are 1/2 wide spaced 1-3/4 apart with a top hole diameter of 1/2. Manufacturer : C.E. Smith Manufacturer Part No : 10190G40 UPC : 768296009540