Pro Penn Marathon Extra-Duty Tennis Balls, 3 Ball Can (4-Pack) red and black Effective eyepiece: 16mm

Effective eyepiece: 16mm

and slide backward to decelerate and brake

13500 BTUs

Brand: Perimeter Technologies

Pro Penn Marathon Extra-Duty Tennis Balls, 3 Ball Can (4-Pack) red and black Effective eyepiece: 16mmBrand: Penn Features: Official Ball of the USPTA for over 37 years longest running endorsement in tennis history. USTA approved 3 Balls to a Can, 4 Cans to a Pack = 12 Balls Total Publisher: Pro Penn Details: Pro Penn Marathon 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 #1 choice of the USPTA Teaching Pros because