Penn Tour tennis balls* are high performance tennis balls, used in 4 out of the 5 largest tournaments in North America. These premium tennis balls are covered with Penn’s exclusive LongPlay® felt for extended wear, and feature our Smart Optik® high visibility felt treatment which makes it 19% more visible than a standard tennis ball. Penn’s premium line of balls are the most technologically advanced tennis balls in the world, providing players with optimum core and felt technologies for the perfect balance of consistency, longevity, and overall playability. Available in both a 3-ball can (extra-duty, regular-duty, and XD high altitude) and a 4-ball can (extra-duty and regular-duty). *Penn Tour tennis balls are USTA and ITF approved.