This straight 12 inch Black Rubber Roller by Yates is designed to give the boater the ease of loading and unloading. Rollers will typically mount along the center line of the boat one cross members using 12 inch Galvanized Roller Bracket. To hold the roller into the bracket we offer a Stainless Steel Roller Shaft 13.5 inch long and a Zinc Plated Roller Shaft 13.5 in long 5/8 inch Diameter which run through the 5/8 inch bore in the 12 inch straight roller. Each end of the roller shaft would be secured by 5/8 inch Zinc Plated Boat Trailer Roller Shaft Pal Nuts. This bracket assembly is then bolted or u-bolted to the trailers cross-member. Make your measurements and check out our Boat Trailer U-Bolts and Trailer Bolts to pick out the correct galvanized or stainless u-bolt or bolt you need! The straight roller is most common on flat bottom boats like skiffs or aluminium jon boats. The support and assistance provided by the the roller makes loading and unloading must easier. MADE IN THE USA!