We are very careful about safety, American DOT certification puncture test / China GB safety certification Name Motorcycle helmet Material ABS Brand Aishi helmet Applicable age group Style:13 Size :M, L, XL, 2XL, 3XL Product volume 39.0 cm * 29.5 cm * 28.6 cm Product weight 1.4kg please note: The size of the half helmet is 34*24*24cm, it may not be suitable for everyone Full helmet size chart: Head circumference below 58 is recommended M head circumference 58-59cm recommended L head circumference 60-61cm is recommended XL head circumference 62-63cm is recommended 2XL head circumference63-64cm is recommended3XL [Generally it is recommended to shoot L, wear glasses or a remote face, suggest a size larger]