Breeana Geering Pro Edition Formula Four Wheels. Spitfire Formula 4 features more speed and control on all surfaces, unmatched flatspot resistance, smooth anti-stick slide, high rebound compound. 100% true performance urethane. The Conical Full is a wider version of the Conical Shape. Wide riding surface, cut in sidewalls to decrease weight. A solid, controllable shape for all terrains. 53mm x 33.5mm, 99A.