Premium Service inner tubes are manufactured to the highest quality. This tube is for ATV/UTV vehicles and will work in Radial Tires. The size marked on the tube is 21x11R8, this 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: 22x12R8, 21x11R8, 21x12R8, 22x11R8