A penis ring is a ring worn around the penis, usually at the base. The primary purpose of wearing a penis ring is to restrict the flow of blood from the erect penis in order to produce a stronger erection or to maintain an erection for a longer period of time. Genital adornment is another purpose, as is repositioning the genitals to provide an enhanced appearance.
Commonly called a "penis pump", a vacuum erection device, or VED, a penis pump enhances the size of the penis by placing a specially designed solid tube over the penis that is sealed at the base. Squeezing the pump's bulb creates negative pressure that expands and thereby draws blood into the penis.