Trans American 23x8.50-12 / 23x9.50-12 / 23x10.50-12 Inner Tube with TR-13 Straight Valve Stem Heavy duty inner tube for tire sizes 23x8.50-12, 23x9.50-12 and 23x10.50-12. TR-13 Straight valve. For use in radial and bias ply tires. Fits radial sizes 23x8.50R12, 23x9.50R12 and 23x10.50R12. ISO 9001 manufactured.