Good alternative to the office chair

I bought the ball because I am pregnant and could no longer sit on my office chair. The ball very well relieves the hips and the pelvis, so that the seats is very pleasant.
The accompanying description is very easy to explain and can be easily implemented. One should actually leave 24 hours pass before inflating it to the specified value.
The smell of gum leaves after also so slow, but I feel that as less disturbing. The ball can be inflated very tightly and keeps the air well.
If someone is looking for a good alternative to an office chair, I can only recommend the ball. He even fit in my little car (inflated)