Penis pump devices comprise of a cylindrical body which fits over the penis with either a motorized or manually operated pump that creates suction. As the device sucks out the air around the penis, blood is drawn into the penis eventually making it erect. The theory behind penis pumps as penis extender devices is drawn from the effect of increasing the blood capacity of the penile shaft through repetitively using the penis pump to draw excess amounts of blood into the shaft. A far more effective method of penis extension or penis enhancement involves the princple of traction rather than penis pumping or penis vacuum methods. The AndroPenis is the only penis enlarger device that holds a medical certification guarantee. In this method penis enlarging is achieved by wearing a device for hours each day. The device applies a certain amount of pulling force to the penis shaft which, over time causes the cells in the penis shaft to expand and multiply.