2-Pack Lawn and Garden, and Scooter 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 is for lawn and garden, cart, scooter and utility tire applications. 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: 16x6.50-8, 16x7.50-8, 16.5x6.5-8, 18x6.50-8, 18x7-8