A constrictor ring made of a flexible but resistant material adapted to surround the entire base circumference of the penis tightly, acting in this way as a constrictor device that prevents blood from escaping from the penis, thus maintaining the erection, wherein the constrictor ring has an adjuster to adjust the diameter of the ring; a grip that allows the user to firmly push the constrictor ring towards the pubic joint in a precise position and with a sleeve made of a rigid material that surrounds the ring in a position that matches the urethra when the ring is correctly placed, thus protecting the urethra against possible damage when the ring is adjusted.