Adjustable Venous Leak Constriction Loop. For the man who can naturally get an erection but find that their erection does not last long enough for satisfactory intercourse. This is often due to a condition known as venous leak, using VenoSeal may be the solution! VenoSeal is an Adjustable Constriction Loop that is placed and tightened at the base of the penis. With proper tension, the VenoSeal device is comfortable, but also provide enough additional pressure to prevent blood from flowing back into the body, thus maintaining the erection.