This review is from: Ironman 75cm Deluxe Stability Ball (Silver) (Sports)
As other reviewers have mentioned this ball is not even close to 75cm. I wasn't sure what size I needed, so I bought the 65 and 75 cm balls. Once inflated they are the exact same size. The instructions say to re-inflate after a day to account for stretching but this makes no difference.
The enclosed pump is somewhat useful for topping up the ball but you really need another air source for the initial inflation. I used a 4" floor pump for inflatables and even that took 5+ minutes per ball.