15" Galvanized Spoke Trailer Wheel. The exact size is 15" x 6" 5 lug on 4.5" bolt pattern. Center hole diameter is 3.3 inches. Back Spacing 3.5 inches. The Offset is zero. Max load is 2600 Lbs per wheel. This listing is for the wheel only. Most common tire sizes mounted on this wheel are 205/75R15, 205/75D15 (F78-15), 225/75R15, and 225/75D15 (H78-15). If ordering center caps the size you would need is 3.30 inches.