Trans American 18x8.50-8 18x9.50-8 Inner Tube with TR-13 Valve Stem 18x8.50-8 / 18x9.50-8 inner tube with TR-13 straight valve stem. ISO 9001 Manufactured. A quality Trans American product. For use in radial and bias ply tires. (18x8.50R8 / 18x9.50R8)