Electro Sex Cock Rings are crafted from solid metal bar to ensure a fine smooth finish. Only two of the cock rings are used but the Electra Rings Pack consists of five different size rings to accomodate different size and fit variations. Use one ring at the base of your cock and one further up the shaft. Alternatively you can use one cock ring in conjunction with a uni-polar anal probe or urethra probe. Use electro conductive gel with this item. You will need an ElectraStim erotic electro stimulator to use this item. If you are using a different power box and your cable does not have the 2mm pin connector you will need an adapter kit. Five different size rings measure approximately 1.4 inches, 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches from smallest to largest in diameter. Each ring is made from a solid bar of aluminum.