Product Features:ABS shell material-strong and durable anti-collision, good comprehensive protection performanceHigh-density EPC buffer layer-high-density foam is light, shock-resistant and warm, with good cushioning effectZipper and detachable scarf-cool in summer, keep warm in winterAdjustable elastic bolt-can withstand strong, protect the safety of the headMulti-segment firm buckle-quick grip for convenient and safe tightening without pressing the skin, free adjustment Product specifications:Name: Old-fashioned helmet, half helmetMaterial: ABS engineering plasticsHead circumference: 56-61cmsize: one sizeApplicable season: four seasonsApplicable people: adult/male and femaleColor: black, light brown, dark brownWeight: 640G The correct method of measuring head circumference:Using a soft ruler to pass the forehead (above the brow bone) and the posterior protuberance point around the head will also be counted. The accuracy of the measurement is your head circumference, and then you can choose a helmet according to your needs. packing list1*helmet customer service:★★If you want to know more information, please feel free to contact us. Click to enter our store to see more quality products.★★If you are satisfied with my product, I hope you can give us a score. This is important not only to me, but also to other friends who need this product.