2 Front & 2 Rear Lawn and Garden tubes for BIAS tires Made with high quality rubber Made to stretch to fit multiple sizes TR13 straight rubber valve stem (.453 Valve Hole) See Product Description for Compatible Tire Sizes Premium Service inner tubes are manufactured to the highest ...2 Front & 2 Rear Lawn and Garden tubes for BIAS tires Made with high quality rubber Made to stretch to fit multiple sizes TR13 straight rubber valve stem (.453 Valve Hole) See Product Description for Compatible Tire Sizes Premium Service inner tubes are manufactured to the highest quality. This tube bundle is for use in all 4 tires on a lawn mower, 2 for the front and 2 for the rear. The size marked on the tube may differ from the size needed as most inner tubes are made to stretch in order to fit multiple tire sizes, according the manufacturer this tube will fit on the following tire sizes: Fits Front Tire Size: 15x6.00-6, Fits Rear Tire Sizes: 20x8.00-8, 20x10.00-8, 20x8-8