C.E. Smith 1-1/2" Wide Keel Base Roller Assembly f/2" - 2-1/2" Tongue. It Specifications for C.E. Smith 1-1/2" Wide Keel Base Roller Assembly f/2": Manufacturer: C.E. Smith Color: Silver Features of C.E. Smith 1-1/2" Wide Keel Base Roller Assembly f/2" Spool roller supports your boat's keel as it sits on the trailer Prevents the bow from making contact with your winch Eases loading and unloading of boat Helps to absorb road shock while boat is being trailered Bracket lets you bolt roller assembly onto the tongue or frame of your boat trailer Requires 7/16" fasteners (not included) Sturdy 1/8" galvanized steel bracket resists corrosion Black rubber roller delivers long-lasting performance : Roller length: 4" Shaft diameter: 5/8" Diameter of mounting holes (each): 7/16" Spacing of mounting holes: 3" apart on center Typically installed flat on the tongue of a boat trailer this spool roller bracket assembly stabilizes the keel of the boat during trailering. Package Contents: C.E. Smith 1-1/2" Wide Keel Base Roller Assembly f/2" C.E. Smith 32100G: 1-1/2" Wide Keel Base Roller Assembly f/2" - 2-1/2" Tongue