If you play on a hard court surface, you need Extra Duty tennis balls. Due to the unforgiving nature of those courts you need a ball that will wear down less quickly. Extra duty balls have a thicker felt, that is woven not as tightly around the ball's core. This means the felt will perform better, for longer.

Developed for hard, abrasive court surfaces, Extra Duty tennis balls have a thicker felt woven a bit looser around the core to withstand shearing. That means that the felt on these balls are less likely to fluff up as they are played.

Generally, extra duty balls are more durable because of their thick felt. The extra felt will mean that the ball will last longer on these demanding surfaces. Extra duty balls will have a longer lifetime, but they will not play as fast as regular duty balls.

Founded in 1899 in Erie, Pennsylvania, the original manufacturer of Penn Tennis balls was the Pennsylvania Rubber Company of America, Inc. Initially a tire manufacturer, the company relocated to Jeanette, Pennsylvania in 1903 and in 1910 began producing rubber balls for a wide range of sports including tennis.

Down over time you can see that some of these get really kind of fuzzy. And hairy. And kind of poofy. And that's a pretty telltale sign that a ball has been played with quite a bit.

The numbers on PENN balls, or any other balls for that matter, are for identification purposes only, nothing more. When your ball rolls onto the court next to you knowing which ball is yours can be determined by the number on it. The numbers on balls are not a rating system--a PENN #1 is no different than a PENN #4.

Extra duty is a punishment. These duties may be required to be performed at anytime and for any length of time. The duties may include performance of fatigue duty or any other duty.

OFFICIAL BALL: Penn Championship is the Official Ball of USTA Leagues, so you know you're playing with high quality and consistent ball. Available in extra-duty felt, regular duty felt, or extra-duty high altitude felt.

Two kinds of Penn tennis balls are used at the Western & Southern Open. The ATP World Tour uses extra-duty balls, while the WTA uses regular-duty tennis balls.

You need balls which are durable and easy to play with . They should have a bounce which is in line with your playing ability and be a little slower (not compressed). You'll be looking for a ball which lasts longer . It should have good bounce and you should feel in control when you hit it.

I have a strix on one and he said well I also have a Swick's on one. We would not know whose ball is who unless. We put another identifiable mark which is generally a dot or two dots on the ball.

Are there different types of tennis balls for different court surfaces? Absolutely! While you may be used to standard pressurized tennis balls, other varieties include “extra duty” for hard courts, “regular duty” for clay courts, and “high-altitude” balls for playing at elevations of 4,000 feet or higher.

Short Answer: That depends. It is up to the commander to allow the Soldier to go on leave. Imposition of punishment begins immediately if a later start date is not stipulated during the announcement of punishment.

Extra duties involve the performance of duties in addition to those normally assigned to the person undergoing the punishment. Extra duties may include fatigue duties. Military duties of any kind may be assigned as extra duty.

The same goes for Dunlop, Penn, and other brands. So why is there a printed number on each tennis ball? The answer is for the purpose of identification. When playing on a court, you will definitely experience your tennis ball rolling, bouncing (or flying for beginners) to the court next to you.

WILSON Legacy All Court Roger Federer.