Spitfire Formula Four Conical Full 97A. Formulated for a softer, faster ride. Unmatched flatspot resistance. Designed for every spot. Grips or slides where you need it. 100% true performance urethane. A wider version of the conical shape. Wide riding surface. Cut in sidealls to decrease weight. A solid, controllable shape for all terrains. 58mm x 37mm, 97A.