Trans American 31x10.50/11.50R15 / 32x11.50R15 Inner Tube with TR13 Straight Valve Stem Quality Trans American combination 31x10.50R15, 31x11.50R15, 32x11.50R15 inner tube. Also fits 30x9.50R15 and 265/75R16 tires. The TR13 straight rubber valve stem, is the most popular stem for passenger and light truck applications. For use in radial or bias ply tires.