Improved grade steel balls

Arch support

Prevents arthritis from uneven cartilage wear

yet won’t pack out over time—providing our highest level of impact cushioning

Wrap Cupsole construction

Spitfire Formula Four Conical Full 99DU Skateboard Wheels Natural/Blue 56mm Size:56mm Improved grade steel ballsDescription: Spitfire urethane was developed to combine all the desired properties of a performance wheel without sacrificing any one attribute at the expense of the customer. The original Spitfire head is one the most recognisable logos in the history of skateboarding. features: size: 56mm. Durometer: 99a. Width: 36mm. Set of four.