A Tennis Ball Pressurizer is needed to keep the pressure inside tennis & padel balls, since balls are made of porous rubber and leaks air. Tennis and padel balls looses around 20 % of the pressure after one hour of play, and this process then continues for every hour the balls are out in athmospheric pressure. To be able to keep & restore the bounce in tennis & padel balls, they must be stored under pressure, and thats exactly what a tennis ball pressurizer does. (sometimes also called tennis ball saver).
