Give your students professional-caliber tennis balls at a fraction of the cost thanks to minor cosmetic imperfections! Wilson Extra-Duty Championship Tennis Ball rejects become Wilson Practice Tennis Balls, giving your students some of the best balls on the market during practicing and skills testing. This is the most popular practice tennis ball we offer! Duraweave technology allows them to withstand punishment from courts and racquets while retaining stellar performance. Optic Yellow color for exceptional visibility. Available in a Can of 3 and a Case of 72.