The top ring is striped over the hard penis and the cuff is tightened. after that you pull the second loop over the testicles and the lower cuff is tightened strong so there is no pain (tighten by feel - risk of congestion of the veins). caution: you should tighten the cuff careful so that the skin is not pinched.features: black rubber round cord made of nbr - elastomer (nitrile), ø 5 mm, hardness of 70 shores. high strength and elasticity. very resistant against oils, gasoline and heat. the noble cuff is made of hard-aluminium and treated with an anodized color. use a disinfectant for cleaning such as malesation cleaner toys & body.