Description: Material: The bike helmet is made of a sturdy PC shell and a high-density EPS foam inner shell, which helps absorb impact and protect the head in case of collision. Safety for protection: Equipped with USB rechargeable and detachable rear LED lights, it has three different lighting modes: stable lighting, flashing, and fast flashing. It helps to warns the car and help other riders behind you clearly identify your direction, making it safe and brighter to ride. Breathable: The bike helmet adopts a ventilation design with 18 ventilation openings, allowing air to circulate and maintain coolness. Adjustable: The bike helmet can be used for different sizes of male and female heads. The head circumference is 22.83 to 24.41 inches (57 to 62 centimeters). The quick release button on the back can help you easily and quickly put on or remove the helmet. Wide application range: The soft inner lining can absorb sweat from the head, reduce unpleasant odors caused by sweat, and help maintain good comfort. The internal pad support is detachable and washable, keeping it clean and cool all day. Specification: Material: Shell PC+Internal EPS Technology: In Mold Color: As shown Head circumference size: Approx.57-62cm/22.44-24.40 inch. Inner width: Approx.18cm/7.08 inch. Inner length: Approx.23cm/9.05 inch. Weight: 260g Ventilation holes: 18 Package Includes: 1 Piece Helmet. 1 Piece USB Cable.