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. - 3-piece penis ring set - Small: inner diameter: 3.4 cm - Medium: inner diameter: 3.8 cm - Large: inner diameter: 4.4 cm - Thickness: 1 cm - Made from phthalate & latex-free silicone - Waterproof