I bought one of the high end Dr. Kaplan pumps with the electic motor and all the cylinders that was needed to my past size now I have since had to buy larger cylinders and I am quite larger. But it did not happen over night , just after one week or month. It has taken months, You do not go into the weight room and lift for a week and say lifting weights does not work! I am not advocating that it is for every body but if you take it seriously and used a structured regular regiment you will see results. I myself and my lady have enjoyed my results. Toby