Expensive but worth it.

I bought these years ago for my ball machine and they were fine. They eventually wore out and I tried a cheaper alternative, but those balls were junk from the start. I bought these again and would only recommend these from now on.

Bought for use in my Proton ball machine, previously used Gamma balls from Amazon but they gave off a ton of felt fluff and degraded fairly quickly. These Tretorn balls are holding up much better - less fluff and more consistent bounce.

I had not used Tretorn nor pressurlessm balls since I was a kid but was so pleased with the initial bag that I bought another. They adapted very quickly to our ball machine and had a quality bounce and spin on our court. Have kept their cover and shape well after several weeks steady use. When needed, I would not hesitate to replace them with another bag.

These balls are great. I'm on my 3rd bag. I originally bought them to avoid throwing away a plastic can every day. They bounce well and last a LONG time. My doubles partners are fine with them. They cost a little more, but end up saving a lot of money. Eventually the covers fall apart-- after probably 20 uses of hard hitting .