This code, when present, appears after the size marking. The code comprises three characters, two numbers and a letter, e.g. 67 H, known as a service description. The two-digit number is a code for the maximum load carrying capacity of the tire. The letter is a maximum speed rating indicating the maximum speed at which the tire may be used with maximum load when the maximum listed inflation pressure is used. Shinko Does not recommend or endorse exceeding the safe, legal speed limit. The load index/speed symbol indicates the speed at which the tire can carry a load corresponding to its load index under conditions specified by the tire manufacturer.