The Silicone Collar is made with premium soft silicone, featuring a flat .80" wide surface which pushes everything forward, maximizing appearance while providing comfort. Rock Solid cock rings enhance size and thickness for longer, harder erections, and completely body-safe. Approximate Product Dimensions: Small - C-Ring, Width/Diameter: 2.5 in. (6.4 cm), Unstretched Inner Diameter: 1.7 in. (43 mm), Depth: 0.8 in. (19 mm) Medium - C-Ring, Width/Diameter: 2.5 in. (6.4 cm), Unstretched Inner Diameter: 1.88 in. (48 mm), Depth: 0.8 in. (19 mm) Large - C-Ring, Width/Diameter: 2.75 in. (7 cm), Unstretched Inner Diameter: 2.0 in. (51 mm), Depth: 0.8 in. (19 mm)