Rubber Master Brand ATV Tube TR4/6 Metal Valve - 8 inch Combination Size Fits 18x8.50-8, 18x9.50-8, 22x11-8, 21x12-8 Designed for ATVs, etc. Fits Sizes: 18x8.50-8, 18x9.50-8 21X12-8,22X10-8 22x11-8, 22X12-8 Tube has a TR4/6 Threaded Metal Valve May be used in BOTH Radial and Bias Tire Applications