Road Readyheavy-duty keel rollersprovide protective support for your boat’s hull while it’s on the trailer, and allow easier launching, centering, and retrieval of the boat.These durable, protective rollers are for heavy-duty useMolded rubber over a steel tube with nylon end insertsGradual inward taper and “V” cut eases loading and launching of heavier boatsPlastic inserts are included to protect from mounting hardware damageNon-marring prime rubber compoundDimensionsShaft DiameterBulk Packaging10″5/8″11216-112″5/8″11217-1