Hot Dipped and ready for all that nature can throw at it. Galvanized for long-lasting life in any environment. This 15 inch, Heavy Duty Trailer Rim will give your Boat Trailer the rugged Saltwater or Freshwater Protection it needs. This 5 Bolt, (5 on 4 1/2 ) Bolt circle rim is fit to match 15 inch tires of all capacities. Common trailer tire sizes for this rim are ST205/75-15 and ST225/75-15 in either bias ply or radial.