The Pro Penn Marathon Extra Duty High Altitude Tennis Ball is Penn’s longest lasting tennis ball featuring exclusive Encore Technology for a 22% longer lasting core and high tenacity LongPlay Felt for extended play. Pro Penn Marathon is the official ball of PTR because of its guaranteed longevity, durability and visibility.

• USTA approved
• Official Ball of the USPTA for over 37 years
• Can of Tennis Balls - 3 balls per can
• Extra-Duty High Altitude for higher altitudes
• Top of the line core and felt technologies