Formula Four Urethane – Formula Four urethane is unlike any other. Both in the streets and under high-speed stress tests in Spitfire's lab, Formula Four wheels retained more material, coned less and kept their original shapes and sizes longer than any other wheel.

Radial Shape – Round edges, slim to medium riding surface offers a quick, responsive , round edge shape.

Wide – More traction and stability at high speed so you'll be less likely to slip out of your line.

Smooth Surface – Smooth wheels have less surface friction than treaded wheels and are easier to slide.

97a Durometer – Offers more grip than harder wheels and more slide than softer wheels. Great for beginners wanting more control on smooth surfaces or for filmers looking for a smooth roll.