Designed for maximum comfort, the Perfect Fit Harness is made with soft nylon and Luv Touch materials that prevent chafing and feel great against the skin. The durable 4-way adjustable straps feature an easy-close clip and fit thighs up to 30-inches (76 cm), while the included waistband extension fits waists up to 68-inches (173 cm). Three metal snaps secure the metal O-Ring and hold everything in place even when the action heats up. The three included silicone O-Rings allow you to interchange a range of dildos with a diameter up to 2-inches (5 cm). Sizes O-rings: Small: Inner diameter: 2.8cm Outer diameter: 3.9cm Medium: Inner diameter: 3.7cm Outer diameter: 4.8cm Large: Inner diameter: 4.7cm Outer diameter: 5.9cm