… READ ONThe 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
