Osbon VenoSeal Constriction Loop.VenoSeal Constriction Loop for the treatment of Venous LeakAn adjustable constriction loop for the man who can create a natural erection, but the erection is not firm enough for satisfactory intercourse. An adjustable constriction loop can be used to prevent Venous Leak.Venous Leak is the result of the penile veins inability to keep blood from flowing back into the body. By placing the device comfortably at the base of the penis, the VenoSeal provides additional pressure to prevent blood from flowing back into the body, thus maintaining the erection.