The top ring is fed through the erect penis and the cuff is tightened, the second loop goes over the testicles and the lower cuff is tightened - do not over tighten and take caution to not pinch the skin. The aluminium-plug is then inserted into the anus. The rubber cord is 5mm in diameter and made of NBR-elastomer (nitrile), very resistant against oils, water based and silicone based lubricants.