Hypoallergenic silicone penis ring.

Penis rings, also called constriction rings, are used for the premature outflow of blood from the penis (called venous effusion or veno-occlusive dysfunction). 

Uniform compression in the base of the penis counteracts premature blood discharge. This results in a slight obstruction of the blood flow which favors the strengthening of the erection. 

A little tip on choosing the size of the ring: you should start with the largest size and gradually reduce the size depending on the effect. Remember that rings can be worn for no more than 30 minutes, as they can cause circulatory disturbances.