Spitfire Team Floral F4 99 Classic Wheels 52mmManufactured with the quality high performance, Formula Four urethane that lasts longer, withstands more abuse and performs superior to all other wheels. Designed to combine all the desired properties of a performance wheel without sacrificing any one attribute at the expense of another. 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