The flat design of the rings is very comfortable and safe. The CB-6000S is made of medical-grade polycarbonate. It\'s lightweight, hypoallergenic and durable. The cage is ventilated to guarantee hygiene and has an opening that lets you urinate normally. The different ring sizes and spacers that come with each packet mean you can adjust the fit to your individual wishes. The CB-3000 denies you the freedom to touch your own genitals and gives the key-holder absolute control over the sexual satisfaction of both partners.  Length: 76 mm Inside diameter: 37 mm Ring sizes: 50, 47, 44, 41 and 38 mm