12R15/16 33x12.50r15 Firestone Brand Tire Inner Tube with Tr13 Rubber Valve Stem LT. Truck Fits Sizes: Fits many 12R15/16 33x12.50R15 Tube has Standard TR13 valve stem: Straight rubber valve, the most common stem style, measuring approx. 1.38 For Radial and Bias Tire Applications