The Endow Deluxe Vacuum Penis Pump System is one of the best penis pumps we carry here at ShopInPrivate.com. This powerful vacuum therapy system helps you regain a natural erection and the ability to have intercourse. This electronic penis pump provides a steady vacuum with the push of an on-off button, allowing you to create intimacy without dealing with a complicated penis pump. The Endow System creates blood flow to the penis, creating a strong, firm erection that is held in place with one of the included cock rings. Four reusable constriction rings are included. They help you maintain an erection after pumping by constricting blood flow from the penis. You can use constriction rings for up to 30 minutes, allowing you an unhurried sexual experience. To use the Endow Penis Pump: Choose a comfortable fitting penis ring from the four included Pull the ring onto the base of the cylinder Insert penis into the cylinder Push the button once to start the electric pump Vacuum suction will draw blood flow into the penis to increase firmness Press the button to stop the pump when desired firmness is achieved Use the tabs to pull the constriction ring down and onto the penis The Endow Penis Pump System is easy to use, and effective for erectile dysfunction (ED). The system also comes with a manual pump, so you can pump with the press of a button, or by pulling a handle to increase suction. This is the most versatile pump we've seen. Takes 4 AA batteries, not included.