The tennis ball repressurizer allows you to put your 4 tennis balls in a pressurized environment at the end of every game. Your tennis balls will thus not lose pressure between games anymore. That means you will be able to play 3 times more with the same tennis balls.
The repressurizer has an integrated pump that allows you to recreate a "new can" environment at the end of every game. It also has a patened cover that will ensure hermiticty within your tube.