C.E. Smith Double U-Bolt Bolster Bracket - 8-3/4". 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. Specifications for C.E. Smith Double U-Bolt Bolster Bracket: Manufacturer: C.E. Smith Color: Silver Package Contents: C.E. Smith Double U-Bolt Bolster Bracket C.E. Smith 10190G40: Double U-Bolt Bolster Bracket - 8-3/4"