Most of Yamuna’s balls come deflated, so you will need a pump to use them. (Those that do not come deflated all the way, do not deflate all the way when using or traveling.) Yamuna specially designed a pump that is small and powerful enough to inflate the PVC plastic balls. This pump is small, light and perfect for travel. It comes with a removable needle, so you can also deflate your balls.
Many other sport pumps will fit into the nozzle of the ball, but they may or may not work to inflate the ball and there is a risk of damage. I have had numerous students push in the valve on their Yamuna ball with another sports pump, causing it to no longer hold air.
Note: do not stick metal needle into the air vent at the back of the bulb. If you purchased a Yamuna pump and it doesn’t inflate, chances are someone put the needle in the pump air vent. This has been the case over 20 times in my Yamuna career, including at my own house! Recommended: keep the pump stashed away from kids 🙂