I purchased my Ab Circle Pro 2 days ago and already it has become unusable. Initially I noticed that the left kneepad pivot was attached at a slight angle, unlike the right kneepad. The left kneepad will not swivel while the right pad spins freely. I overlooked this defect and have used it for a few hours now. In this short time, the paint on the frame that comes into contact with the rollers has worn off, and the rollers have now developed flat spots and will not spin. I am not excessively heavy (I weigh 150#) so I think this product was not made to actually be used by human beings. PLEASE SAVE YOUR MONEY!!! DO NOT BUY THIS SHAM OF A PRODUCT!! read full review »