They are good balls ... butNovember 9, 2008 As far as a pressureless ball these are very good. They are well made and definitely work better in a ball machine than regular tennis balls. However, and this is a BIG however, I do not recommend using these balls unless you play tennis regularly and have good form. I am in good shape; however, I have not been playing tennis as often as I used to. I got a tennis ball machine and over did it the first couple of times out. These balls compounded the problem now I've been unable to play for 6 months and still have a problem with my forearm. You can definitely feel the difference when you hit the pressureless balls. If my arm doesn't feel better by next year I may be having surgery. So just be careful and take it easy at first if you use these balls.
