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 setSmall: inner diameter: 1.33""Medium: inner diameter: 1.5""Large: inner diameter: 1.75"".37"" thick.Made from phthalate & latex-free silicone.Waterproof.