These are just rock solid balls for your tennis machine. They did bounce less than my old/bald Gamma's but that's kind of expected. I love the white/yellow set as they won't get mixed up with neighboring players at the courts and they are very bright.

From someone who has destroyed many old fashioned tennis balls

Great product. I buy 2 or 3 bags each year for my ball machine.

I have used these presureless ball for years to teach with. Its very cost affective and they last a long time.

I just bought these and at the last minute the company said I could take the all-yellows, which they had in stock, or I could wait for another month or so for the grey and white. Right away, I noticed, they don't have nearly the same pop as the grey and yellows I have had for about a year. I thought maybe after they wore in, it would change, but nope. Makes it tough to use them with my other Tretorns. The originals are still the best pressureless ball used to date by far.