The size 275/25 R21 is reserved for tyres designed for sports vehicles. The first number (275) is a tyre's tread width expressed in millimetres. The next number is a designation of the tyre's profile height expressed in percentage (25% of 275 millimetres of the tyre's tread width). The "R" in tyre's size means that the tyre is built using a radial construction. Last parameter in the tyre's size is the diameter of the wheel's rim (in inches) on which the tyre can be installed. With us you will make the best purchase of the tyres in size 275/25 R21.