As the name suggests, this tennis ball is designed to last longer than most. It feels bad chucking one-match used balls (I give them to pupp-ay or toss 'em in a practice hopper) but that's been a fact of tennis life.
Penn’s newest tennis ball, the Pro Penn Marathon, not only offers greater longevity than past Penn balls but also better durability and visibility.
Encore Technology is the core compound that maximizes longer-lasting playing properties. By using a proprietary blend of natural and man-made polymers, ball softening is limited. The core stays fresher longer, playing fresh from the can longer.
Pro Penn Marathon has a 22% longer lasting core compared to Penn’s original Pro Penn+ tennis ball (and those have actually been among the best for hopper ball longevity according to a few teaching pros I've spoken with).
The new ball will hit stores worldwide January 2012 and will be offered in Extra-Duty (for hard courts), Regular-Duty (for soft courts) and Extra-Duty High Altitude.