Like Penis developers a Penis Enlarger will increase your length and girth. Penis enlargers are a pump type enlarger that forces the air out of a container drawing the blood of your penis into the outer chamber of your shaft. Much like a muscle in your body your penis remembers the size it managed to get to and over time will continue to reach that size. Over time you can increase your penis length by up to 2 inches and girth by up to an inch. A penis enlarger can increase your stamina and how hard your erection gets.