Details Composition : Titanium Steel Size & Fit S Diameter: 16.5mm, M Diameter: 17.3mm, L Diameter: 18.1mm, 18k Gold Plating Cm Inch Size US Length S 4 2.0 M 6 2.1 L 8/10 2.2 S 4 5.18 M 6 5.43 L 8/10 5.68 Care Instructions Avoid contact with water, other liquids and metals.