Wilson US Open Extra Duty Tennis Balls 3 Pieces

Wilson us open high altitude tennis balls is made from premium woven felt and performs ideally on indoor and outdoor hard surfaces. For use at altitudes above 3 meters. The us open tennis ball is made with exclusive tex tech industries felt for superior playability, consistency and durability. Standard felt is made for use on all surfaces for maximum versatility for players above 3500 elevation. The Wilson us open ball is also available as a Wilson us open extra duty tennis ball for hard courts, a Wilson us open regular duty tennis ball for clay or indoor courts, or a Wilson us open grass court tennis ball with white felt for grass surfaces. The Wilson us open tennis ball is approved by both the usta and the itf.