Bones STF Retros 103A V5 Sidecut Skateboard Wheels White 53mm Price is for a set of four wheels. 53mm height diameter, 103a hardness rating. Bones V5 custom shape with flatter side edge surface for lock-in grinds. Bones own STF Street Tech Formula urethane. Roll fast, grip when you need to and slide when you want to. High quality urethane and flatspot resistence from one of our most popular choices of wheel brands.