Front tire of motorcycle Terra Force-ef Super of the company Mitas. It is suitable for off-road driving, meaning it can only be used for off-road driving.

Its dimensions are 90/100-21. That is, it has a width of 90mm, a profile of 100, and can be mounted on a 21" rim. The profile in tires, meaning the height of the tire's sidewall, is always referred to as a clean number without a unit of measurement as it is a percentage of the width. For example, a 180/55 tire has a width of 180mm and a profile of 55, meaning it has a profile of 180 x 0.55 = 99mm.

The TT marking comes from the initials of the words Tube Tyres. Tires bearing this marking require an inner tube.