Wow. Just found this thing. It RE-Charges / Re-Pressureizes Flat Tennis Balls, and also keeps new ones at the Correct pressure. It's called "Pressureball" (Is it ok to Post the URL of the Manufacturers Website? If so I will) All the other "Pressureizers" on the market just keep new tennis balls at their correct pressure. But this thing Pumps life back into FLAT balls. You can put up to 20 PSI in this thing. I filled this thing up with old crappy, balls (that are literally 2 years old). I kept them in there for a few days, and played with them the other day and they are literally just as bouncy as New Tennis Balls! I could not believe it. This thing works like a champ. Anyway, just thought I would share my experience with this thing because it works so well. Couldn't be happier. Anyone else tried one?