The Spitfire Camo Classics blend in perfectly with whatever style of skating you take on. Manufactured using a 100% pure urethane compound, Formula Four wheels out-performed and resisted flat spots longer with less wear than all other wheels. Higher rebound for faster speeds over rough and smooth surfaces with a hard durometer for a smoother, faster ride that won't mush out over time. Designed with an exclusive anti-stick compund that gives a fast, consistent, smooth slide all the way through.