Boat Trailer Roller Split Panel Brackets - Galvanized Tie Down Engineerings Trailer Roller Split Panel Brackets are sold in pairs left right to allow use with varied roller widths. Holes on the brackets are sized to work with either 12 or 58 roller shafts. Slots allow vertical adjustment using 719 or 12 U-Bolts for stabilizing the boat on a trailer. Features Hot dipped galvanized finish Slots accept 716 or 12 bolts Roller shaft diameter can be 12 or 58 Sold in pairs left and right California Re