G4Free Wind Cross Adult Helmet Unisex Adjustable Multi Sport Outdoor Mountain Bicycle Cycling Road Bike Helmet Safety Hat/Protecting/Safety Helmet with Visor Material:PC (One molding process)and high density EPS; Inside Material:double-sided velvet lining+ Aluminum Bracket+ Anti-insect absorbent lining. Size: about 9*8.26*6.69 inch ; Weight:7oz. Head circumference:about 55-61cm adjustable. Comfortable cushion lining High-sided article black velvet for shockproof. Adjustable chin strap and clip fastening to make sure the helmet is secure and comfortable , Many channeled vents bring cool air in through the front, allowing it to pass over your head and then flushes warm air out of the rear ports. When you racing outside, climbing the mountain, this bicycle helmet is your first choice ,Universal fit with a brilliant adjustable dial to ensure the perfect secure fit , Snap on visor looks the part and is especially useful when raining or in sunny conditions .