Dunlop Australian Open Tennis Balls 4 ball can The fabric of the game The 1st Grand Slam tournament of the year uses this high-performance tennis ball. HD Core and HD PRO Cloth technologies make it easier to play on all surfaces. Wherever you play, however you train. One thing underpins it all, the Dunlop tennis ball. Obsessively crafted, meticulously engineered, officially endorsed. The Official Ball of the Australian Open. Features: Strong to the core A high-specification re-mastering and re-engineering of the classic Dunlop Fort Core. You get a ball with more durability and a more consistent playing characteristics. Ultimate high-performance felt cloth from Dunlop. Ultra-high-specification and ultra-visible cloth technology engineered for the world's elite tournaments and players.