The delivery of Gymnasikballs went very quickly. Also the inflation went slightly out of hand. Another positive is the fact that the ball a device was attached to inflate. The color corresponds to the on the image, a real eye-catcher, just pink !! The ball has a circumference of 55 cm, is therefore compared with the balance balls in the gym a little smaller. Abdominal exercises can be bad do this. But the ball was primarily designed for back exercises and ensure the ball is designed! The ball is also stable, I have not ever aufpumpem. All in all money well spent!