Prolong & strengthen your erection with soft and stretchy silicone penis rings that gently restrict blood flow for a uniquely sensual experience. Each size delivers a different intensity. Specs: 3-piece penis ring set Small: inner diameter: 1.33"" Medium: inner diameter: 1.5"" Large: inner diameter: 1.75"" .37"" thick. Made from phthalate & latex-free silicone. Waterproof.