Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not 65 cm

I ordered this ball so I could sit on it at my desk. When it was fully inflated, it was barely more than 55 cm. I'm sure it would have been fine for exercise, but not for what I needed. I already have a ball this size. I was disappointed that I had to go to the hassle of returning it because it wasn't even close to the size it was supposed to be.