Pro Penn Marathon Extra Duty Tennis Balls - 24 Can Case Ektelon It contains natural beef serosa

It contains natural beef serosa fibers that provide maximum power

Luxilon 4G Rough is the string used by Alex De Minaur

Suitable for primary school use

The String Tension Tester lets you know when it's time to restring

Tennis enthusiasts know how impressive this string feels when it makes contact with the tennis ball

Pro Penn Marathon Extra Duty Tennis Balls - 24 Can Case Ektelon It contains natural beef serosaPro Penn Marathon Extra Duty balls feature Penns exclusive Encore Technology for a 22% longer lasting core. Ideal for hard courts, this ball also incorporates LongPlay Felt for extended play and features SMART OPTIK felt for enhanced visibility over standard tennis balls. A best seller for many years, Pro Penn Marathon Extra Duty tennis balls are technologically advanced and offer outstanding performance and durability. Pro Penn Marathon Extra Duty