Firestone Brand 18/19X8R8.5R9.5R10R11R8 ATV Tire Inner Tube with TR6 Metal Valve Stem. Designed for outdoor power equipment Go Karts, ATV's Etc. Fits Sizes: 18/19 X8R 8.5R 9.5R 10R 11R8 Tube has TR6 Threaded Metal Valve May be used in both Radial and Bias Tire Applications