Formula Four Urethane – Unmatched abrasion resistance (no flat spots), more controllable grip, lasting speed everywhere, smooth anti-stick slide, longer lasting (holds size and shape longer).

Conical Full Shape – With a wide riding surface and a cutaway design, this shape has unmatched control and lasting speed everywhere.

99a Durometer – More speed and control on all surfaces. Unmatched flatspot resistance. Smooth, anti-stick ride. High-rebound compound.

Smooth Surface – Smooth wheels have less surface friction than treaded wheels and are easier to slide.