The Official ball of the ATP World Tour.The Official ball of the ATP Tour and the 1# ball on Tour used at more ATP Tour tournaments than any other ball. This super-premium ball features HD Pro Cloth and HD Pro Core for ultimate consistency and performance. Perfect for hard courts. This is also the official ball used ATP 1000 Miami Open, ATP 250 Dallas Open, ATP 250 Atlanta Open and at the season-ending ATP NextGen Finals and Nitto ATP Finals. Dunlop is also the Official ball brand of the USPTA. Also available in a high-altitude version.