The Roll-Line FLUIDO 57mm Professional FreeStyle Wheels represent the start of a whole new class of Wheels. This very high quality wheel, is designed to be used on many types of skating surfaces including standard wood floors coated with plastic or poly urethane, but also unusual surfaces like, tile type basketball and volleyball courts, tennis courts (Indoor or outdoor), and concrete or terrazzo surfaces that are more common around the World. The FLUIDO 57mm Professional FreeStyle Wheels are used a great deal internationally, where there are few indoor skating centers like there are here in the USA.