I specifically ordered this because it said it was 75 cm... .it's not. The inflation instructions indicate that "fully inflated" for this ball is 22" ... not 29.5 inches (which is what 75 cm should be in inches). If you're just looking for an exercise ball, that might be fine, but I ordered it to use as an alternative to my office desk chair and it's not tall enough for that. (I'm 5'11" and 75cm was the smallest ball I could use as a chair) That said, it's a nice exercise ball so if the size isn't a big deal for you, it's a good product.