This Stainless Steel Center Cap will complete the look on your clean and new Aluminum Trailer Wheels. This Stainless Center Cap 15 inch trailer Aluminum Wheels with center hole measuring 4.25 inches. In addition, this wheel center cap has movable centers for accessing grease fittings for bearing maintenance. This 4.25 Stainless Steel Trailer Wheel Center Cap will fit the Boat Trailer Wheel 15 inch Aluminum Wheel Split Spoke 6 Lug Rim and Boat Trailer Tire ST225/75R15 Radial on Aluminum Wheel 6 Lug by Loadstar.