The upper ring is slipped over the hard penis and the cuff is pulled tight. Then put the second loop over the testicles and tighten the lower cuff just enough to avoid pain (tighten by feel - risk of congestion of the veins). Caution: Tighten the cuff carefully so that the skin is not pinched. Properties: black rubber round cord made of NBR elastomer (nitrile), Ø 5 mm, hardness: 70 Shore. High strength and elasticity. Very resistant to oils, petrol and heat. The elegant sleeve is made of hard aluminium and is treated with an anodized paint. A disinfectant should be used for cleaning.