Trailer Bunk Galvanized Swivel BracketsHot-Dipped Galvanized Swivel Top Bunk Brackets are common on smaller boat trailers that require not only height adjustment of the bunk boards but also angle adjustment to accommodate the boat hull design. These trailer bunk swivel brackets are hot-dipped galvanized for maximum corrosion resistance. To complete their installation, you will also need lag screws to reinstall the new bunk board brackets and bunk boards. Also be aware that these swivel bunk brackets typically install using either standard bolts or U-bolts that are mounted to the trailer's crossmember. For DIYers and marine technicians alike, it's best to know the dimension of your trailer's crossmember. This way, you'll know which U-bolt size you require for mounting your replacement bunk board brackets.Trailer Bunk Galvanized Swivel Brackets are designed for use with bolster brackets. Trailer bunk galvanized swivel brackets allow trailer bunk and bolster boards to be easily adjusted to exactly match the angle of your boat's hull bottom. Remember, since they are galvanized for protection from the elements, your new bunk board brackets will provide years of reliable service. The brackets include zinc-plated nuts and bolts to secure the brackets. To recap, these bunk board brackets are: Hot dipped galvanized finish provides corrosion protection; Sold as pair; Dimensions: Mounting Face (3 Holes): 1-1/4" long; Swivel Face (1 Bolt Hole): 1-3/4" long; Overall Bracket Width: 3-1/2"; Thickness: 3/32";