1.Two reinforced layers: strong ABS shell resists impact and high quality EPS foam provides shock-absorbing.2.3 Sizes. Medium is for adult and youth. Please choose the helmet size according to the head circumference.3.Suitable for various outdoor sports such as biking, skateboarding, skating, scooter, rollerblade, longboard, hoverboard and so on.4.11 vents provide sufficient air flow, reduce sweating, keep user cool and comfortable.5.Fully adjustable for a custom fit, provided by the crank adjustment dial, 2 sets of pads with different thickness, and length-adjustable chin straps.Our products are made with the highest quality materials and are designed to provide you with the best possible user experience. We strive to ship out all orders within three days of purchase, and the estimated delivery time is 7-14 days.When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specificationsWe want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don't hesitate to contact us. We are here to help and will do our best to assist you.Thank you for choosing our product. We hope you enjoy it