Original clay-style wheel; 57 × 30 mm; precision bearing style. The manufacturer emphasizes sliding and places Premier in the hardest Fo-Mac category. The description mentions brown and black, while the actual selectable choices also include blue. Compression-molded Fo-Mac formulas differ from modern urethane and differ from one another. Sure-Grip says floor material, skater weight, temperature and other conditions affect performance. Fo-Mac products should not be assigned an invented urethane A durometer. The current manufacturer page does not specify the sold pack quantity. Confirm quantity with Diamond before ordering. Photos show an example variant. Select your size or color where offered; confirm stock with Diamond.