Slotted for vertical adjustment and feature non-slip dimples to avoid movement and increase load capacity. Packaged in pairs with swivel brackets and bolts with nylock nuts.Bunk Brackets: heavy 11 gauge hot dip galvanized steel brackets mount 2" bunks on edge. Slotted for vertical adjustment to standard or deep-V hulls.Swivel Brackets: use with adjustable bolster brackets for proper angle of bunk or bolster boards. Packed in pairs with 1/2" x 1" bolts and 1/2" nylock nuts or purchase in bulk.Split Panel Brackets: sold in pairs (right and left) to accommodate any size roller length. Slot allows vertical adjustment for stabilizing boat on trailer. Use 1/2" or 5/8" roller shaft.