Instruct: Classify a given review as either positive or negative.
Query: Body Trends 55cm exercise ball with pump

The pump supplied with the ball was next to useless. The plastic valve supplied to pump up the ball was designed to screw into the pump. I was never able to get the connection tight - the valve just kept turning in the pump. The pump delivered very little air with each pump stroke, and my arms were exhausted before I could get the ball pumped up. Once the ball was partly inflated air leaked out of the top of the pump, and it was necessary to pump very fast in order to get more air into the ball. I managed to borrow a better pump from a friend and was able to inflate the ball further. However, I was never able to inflaate the ball to 55 cm. The fully inflated ball was much smaller than at least three other exercise balls claiming to be 55 cm. I would not recommend this product at all.