Island Rings Double Stacker Ring Glow in the Dark double support stretchy rings. Each ring measures .85 inch in diameter. Comfortable, durable and stretchy erection enhancement rings with pleasure beads. Safe and pure for body and pleasure. Made using phthalate free, non-toxic materials Thermoplastic Elastomers TPE. Island Rings Double Stacker is a registered trademark for California Exotic Novelties. Sex toys and sexual wellness. Wash before and after each use. Always use a water based personal lubricant with this product for maximum pleasure. Important warning: this novelty product is intended as a sexual enhancing aid. Not intended for contraception/birth control or treatment of erection conditions. Use no more than 30 minutes at a time. Allow 60 minutes between additional uses. Do not fall asleep or be under the influence of alcohol or drugs while using this product. Prolonged use without removal may result in bruising to the base or permanent injury to the penis. Consult you physician should any complications should occur and discontinue use immediately.