MATTER provide 3 levels of wheels hardness call F0, F1 and F2. In the past, most of the wheel industry describe the hardness as 84a, 86a ect. The hardness of a wheels is not an exact science and a tolerance around it is needed. When you look at Matter wheels, we will still provide the 2 kinds of information on most of our wheels.
F0 is an 88a, F1 is an 86a and F2 is more like an 84a but always keep in mind that in production there is a tolerance about it that can go around 1 to 2a shore.
Beside these 3 basics, to select a wheel you can also find some other key points to influence your decision.