Tennis Court Supply brings you the best tennis supplies, accessories and equipment to help you improve your game. Shop our selection of Tretorn Micro X Tennis balls, featuring a micro cell technology that maintains bounce and provides a significant life span. Tretorn Micro X Tennis balls are excellent for tennis ball machines and/or regular play. There are 72 balls per case. We guarantee you will notice the difference in your tennis game when playing with Tretorn Micro X Tennis balls. Order a case or several to have on hand now!