Dunlop Grand Prix Extra Duty 24 Clear Cans Traditionally known for being high-quality tennis balls, the Dunlop Grand Prix Hard Court 24 Clear Cans of tennis balls are no exception. These premium tennis balls are made for play on hard court surfaces. A special mix of 14 ingredients creates the secret rubber core formula. Cover that with finely woven felt, and you have a tennis ball that provides outstanding feel and performance every time. 24 cans per case. Features 3 balls per can. Lids not included Sanctioned for ITF and USTA tournaments.