Adult Dual Visor Modular Snowmobile DOT Full Face Flip-up Helmet (White, Large) Retractable tinted sun visor Smooth opening and closing with easy to actuate button Double Pane shield with anti-fog coating Adjustable breathbox and chin skirt included SIZE CHART (Circumference of the largest part of your head, usually just above the eyebrows) in inches SMALL: 21  to 22 - MEDIUM: 22 to 22  - LARGE: 22  to 23 - XL: 23 to 23  - XXL: 23  to 24. Head shapes can affect how a helmet fits. The size chart is meant to be a starting point. Typhoon Helmets allows exchanges for a different size or color. Just return your purchase to us at your expense and we'll send your exchange at no charge to you.