Air Loc Brand Set of 2 Tire Inner Tubes with TR13 Rubber Valve Stems - 15x6.00-6, 15x6.00-6 Fits Sizes: 15x6.00-6 Tubes have Standard TR13 valve stem: Straight rubber valve, the most common stem style, measuring approx. 1.38" long and used in the standard size wheel hole of approx. 1/2"