You can pay more, but you won't find sport and recreation tubes that are more air-tight and enduring than premium RubberMaster Snow/Water/Sport/Recreation Inner Tubes. These tubes are made from the finest rubber compounds to provide long service life and resistance to aging. Plus, they go through a series of rigorous quality checks to be sure they're flawless. Choose the size you need, 1000-20, which is 36 inches in diameter when fully inflated, and 11L-15/16, which is 28 inches in diameter. The tube size that is optimal for you will depend on your own size, and the outdoor activity you're using it foryou may want a smaller pool float tube for swimming than for river rafting or snow sledding.