Set of Spitfire Formula Four Classics Silver Skateboard Wheels in 56mm with a new slightly softer 97du compound. Spitfire Formula Fours are definitely some of the best wheels you can get today, they are formulated for a hard, fast ride and are extremely resistant to flat spotting. Grinds are also made easier thanks to the smooth anti stick slide that the wheels provide.These wheels feature Spitfire's classic shape which is designed to be a good all round wheel for any type of skating and proven for speed and control.