The dimensions are 110/80-19. That means it has a width of 110mm, profile 80, and can be fitted on a 19" diameter rim. The profile of the tyres, which is the height of the tyre's sidewall, is always referred to as a plain number without a unit of measurement because it is a percentage of the width. For example, a 180/55 tyre has a width of 180mm and a profile of 55, meaning it has a profile of 180 x 0.55 = 99mm.
The load index and the speed index are two other important characteristics of the tyres. Specifically, the load index is the maximum load under which the tyres are expected to function correctly and is described by an integer, which corresponds to kilograms, while the speed index is the maximum speed under which the tyres are expected to function correctly and is described by a letter from the English alphabet, which corresponds to km/h. It should be noted that the maximum kilograms corresponding to the load index are per tyre.