TUBOX3 HOLDS THE PRESSURE OF TENNIS AND PADEL BALLS WHEN USED BETWEEN GAME AND PARTY. IT IS THE CHEAPEST, SMALLEST, LIGHTWEIGHT AND MOST USER-FRIENDLY PRESSURE TESTER ON THE MARKET. WORKS WITHOUT PUMPING AS THE FREE SPACE IS FILLED WITH COMPRESSED AIR, THE PRESSURE OF THE TUBOX3 INCREASES UP TO 15 PSI AND THE BALLS CANNOT REMOVE YOUR INDOOR AIR AND WILL REMAIN IN PERFECT CONDITION UNTIL THEY ARE USED NEXT TIME.