Tennis ball

摘要

A pressurized game ball including an air-permeable elastomeric wall defining a cavity containing a compressible inflation gas with the improvement being that the inflation gas includes predetermined mixed amounts of air and sulfur hexafluoride (SF6) gas which effectively enables the ball to retain its pressurized state within a desired range of pressures for a period of time significantly longer than the ball would remain pressurized if the inflation gas were air alone.