Vaupan Mini Exercise Ball, 9 Inch Small Gym Ball with Inflatable Straw for Yoga, Pilates, Stability, Barre, Physical Therapy, Stretching and Core Training, Improves Balance, Strength (Green)

This ball comes with a little straw to inflate it, making it extremely simple to use. However, it's quite difficult to keep all of the air you pump in to inflate it from escaping as you try to enter the plug. I've been re-trying it on and off for a few days and have now filled it to the point where the ball doesn't appear sagging. I'd still like it to be more full, and I'll probably keep trying to get more air into it. I made a bigger yoga ball out of a straw and a hand-pump I had laying around. My problem isn't obtaining enough air in the ball; it's how much air is wasted in the little period of time it takes to insert the plug. This was purchased for physical treatment with a neck injury. It is necessary for me to keep the ball between my head and the wall. I then roll/move over the wall while rotating my head. After 5 minutes, I discovered that the red ball had left tiny markings on my white wall. If I keep doing this, I'll be able to see it.

Serves the purpose. I got what I was expecting. Really good. Easy to blow as well. Not as difficult as how people mentioned in other reviews.

Why is one ball way smaller than the other???

Difficult to open stopper - had to prise open with a tea spoon. Able to inflate using straw supplied but can't get stopper in again quickly enough to keep it fully inflated. Luckily for my purposes full inflation is not required. Ball is very creased as a result of packaging and not sure that creases will come out- especially when not fully inflated. Company sent promptly and colour and size as described.

The ball comes with a plug for the air intake and a straw to blow air into the ball. Unfortunately, when you remove the straw and try to return the plug, much of the air runs out. In addition, the diameter of the straw is slightly smaller than the plug hole so air seeps out while you are trying to fill up the ball. Because of this, it is nearly impossible to inflate this ball to a usable function, even if you are super quick with the exchange. For this reason, I can't imagine why anyone would consider this product, unless they accept the ball being partially deflated.