How the water pump works?

The water pump is an external penile rigidity device that uses vacuum technology to improve and maintain erection quality and duration through regular exercise of the penis.

    The water pump functions by creating a vacuum seal against the pubic area of the user, enclosing the flaccid penis. When the pump is pushed downwards against the body, the bellows compress and water is ejected from the end of the pump via the open valve. When released the bellows expand and the valve closes, creating a partial vacuum inside the pump. This causes the penis to expand and fill with blood, creating an erection. Re-pumping increases the size of the erection.