A two-piece inflatable penile prosthesis is a surgical treatment for erectile dysfunction that uses two cylinders in the penis and a combined fluid reservoir and pump in the scrotum. When the pump is squeezed, fluid moves into the cylinders to create an erection, and pressing the release valve returns the penis to a softer state. Because it does not require an abdominal reservoir, the surgery is less complex and may be preferred for some men. It provides a more natural appearance than malleable rods, though erections and flaccidity are usually not as complete as with a three-piece prosthesis. Satisfaction rates are generally high among men who receive it.