This is a Roller End Bell for your standard 4 inch Poly or PVC Boat Trailer Roller. We sell these individually so you can replace one side if that's what 's needed, however, if you're making a Boat Trailer Roller Assembly from scratch you will most likely need two of these bells. The Blue PVC Bell Roller is used to give additional support and protection to your Boat Hull, and they are typically mounted on the ends of the roller shaft outside of the Roller Bracket Arms. This requires a longer Roller Shaft or Trailer Bolt to accommodate the addition of the End Bells, but it will leave you with a helpful roller on the inside and outside portion of the Boat Trailer Roller bracket to assist in loading and unloading your boat.
5 1/4 inch diameter x 3 3/4 inch diameter on the smaller end of the bell
1/2 inch bore
Matches the 4 inch Blue PVC Roller
Doesn't mark or scratch your boat