When you’re looking for the ultimate beginner’s cock ring kit, the Silicone 3-Ring Stamina Set is the proven choice for hard erections that last and last! With three super-stretchy silicone rings to choose from, this trio is the perfect assortment to help you achieve your maximum potential. Find the perfect size for you and put it around the base of your shaft to gently restrict blood flow and help you achieve the biggest and most intense erections ever imagined. Measurements: Small: Inner diameter: 2.9cm Outerdiameter: 3.9cm Medium: Inner diameter: 3.7cm Outer diameter: 4.8cm Large: Inner diameter: 4.8cm Outer diameter: 6cm