Original Clay roller skate wheels from the ultimate in sliding and feel. Available in original toe tone brown and black. Precision only, 57mm x 30mm. SOLD IN PACKS OF 8! Fo-Mac wheels are retro-style wheels using a compression molding process. The materials used are much different than urethane wheels of today. Thus the same hardness scale cannot be used. The formulas used are unique and different from each other and can offer a different skating feel. Many factors will contribute to the performance of a wheel like this; such as weight, floor material, temperature, etc. Hardest - Premier, Mini-Mac, Freestyle, Slick, Harmony Hard - All Amarican Plus, All American Gold, All American Dream Color: Black