attwood 11217-1 Trailer Boat Heavy-Duty Rubber 12" x 5/8" Shaft Keel Roller, Black Non-marring, durable rubber protects your boat's finish Molded rubber over steel tube with nylon end inserts Extremely tough, designed specifically for heavier boats Inward taper and "v"-cut eases handling of larger vessels Attwood products are both compatible and reliable, engineered and built with a never-fail attitude