Product Details: Type: Intergrally-molded Material:Outside: PC, inside :EPS,Nylon adjust belt Size:About 26*21.5*15cm,fit head : 58-61cm Weight: About 230G Feature: Ultralight/Anti-Sweat/Shock Resistance/Ventilation,Use air cooling make the air free Brethable,Adjustable size,easy to wear and take off Cycling safely, break the wind One-piece molding, edging design, EPS cushioning and shock absorption Low wind resistance, comfortable and breathable