10" L-Type Boat Trailer Bunk Bracket Durable, aluminum replacement bracket works with another 90-degree bracket to stabilize 1 end of an extra-large bunk board on your boat trailer. Installs on level trailer frames with a U-bolt (sold separately). Features: Replaces 4 vertical bunk brackets on your trailer Stabilizes the end of the bunk board when used with additional bracket Requires 1/2" diameter U-bolt (sold separately) for installation Constructed of rustproof, corrosion-resistant aluminum Great for freshwater and saltwater use Made in the USA Specs: Quantity: 4 brackets Dimensions: 10" tall x 5" wide Distance between trailer mounting holes (center to center): 3-9/16" Distance between bunk board mounting holes (center to center): 1-1/2" Plate thickness: 1/4"