Heartless wheels come in a wide range of hardnesses to accommodate every skater. Heartless wheels are sold in packs of 4, in order to give you the best combination possible. The durometer or hardness of the wheel is indicated by the number followed by an "A". The "A" is the type of scale that is used to determine the hardness or softness of a wheel. The lower the number the softer the wheel, the higher the number, the harder the wheel. Our wheels range in durometer from 86a to 96a with the hardness increases every two points.