Features1There is an adjustment knob on the back of the bike helmet to help adjust the heads circumference. 2The helmet is made of thickened multi-density EPS foam material, which can effectively absorb impact energy and minimize the risk of injury to the heads during impact. 3Detachable soft lining and chinpad, comfortable to wear and convenient to wash. 4The riding helmet is made of lightweight materials and is lined with breathable material for comfort. 5Using a professional aerodynamic and ventilation design, the air passes through the bike helmet to help increase speed and keep you cool.SpecificationThis product is made of fine quality environmental protections material and reinforced plastics sheet, with strong impact resistance, aging resistance, not easy to scratch.Features:There is an adjustment knob on the back of the bike helmet to help adjust the heads circumference.The helmet is made of thickened multi-density EPS foam material, which can effectively absorb impact energy and minimize the risk of injury to the heads during impact.Detachable soft lining and chinpad, comfortable to wear and convenient to wash.The riding helmet is made of lightweight materials and is lined with breathable material for comfort.Using a professional aerodynamic and ventilation design, the air passes through the bike helmet to help increase speed and keep you cool.Specifications:Color: white, black (optional)Material: PC+EPSHeads circumference: 540-620mmItem size: 280 * 210 * 140mm / 11.0 * 8.3 * 5.5inItem weight: 243g / 8.6ouncePackage size: 280 * 225 * 170mm / 11.0 * 8.9 * 6.7inPackage weight: 432g / 1.0lbPacking List:1 * HelmetPackage List1 * Helmet