Premium Service inner tubes are manufactured to the highest quality. This tube is for automotive heavy duty truck tire applications and can be use in BIAS or RADIAL tires. 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: 14.00R20, 13.00R20, 13.00R21, 14.00R21