1-1/2" Wide Keel Base Roller Assembly f/2" - 2-1/2" TongueProduct DescriptionThis roller assembly supports your boat's keel for easy loading and safe transport on your trailer. It features a 4", black rubber spool roller and a galvanized steel bracket that attaches to your trailer's tongue. 2 to 2-1/2" trailer tongue.Features:Spool roller supports your boat's keel as it sits on the trailerPrevents the bow from making contact with your winchEases loading and unloading of boatHelps to absorb road shock while boat is being traileredBracket lets you bolt roller assembly onto the tongue or frame of your boat trailerRequires 7/16" fasteners (not included)Sturdy, 1/8" galvanized steel bracket resists corrosionBlack rubber roller delivers long-lasting performanceMade in USASpecifications:Roller length: 4"Shaft diameter: 5/8"Diameter of mounting holes (each): 7/16"Spacing of mounting holes: 3" apart on centerTypically installed flat on the tongue of a boat trailer, this spool roller bracket assembly stabilizes the keel of the boat during trailering.