Trans American KR14/KR15 Inner Tube with TR13 Valve Stem Premium KR 14/15 inner tube for use in farm, industrial and passenger/light truck tires. TR13 valve stem. For use in radial and bias tires. See product description for application information. Fits 6.70-15, 7.00-15,7.10-15, 7.50-15, 7.75-15,8.15-15, 8.20-15 Bias sizes too.