OSdream Adjustable Helmet ABS for Outdoor Sport Please measure your head before make an order. Not Designed to Withstand or Protect Against Real Ammunitionit is not fit for high speed motorcycles to use SizeHead circumference M/L 53-57 cm 21-22.5 inchL/XL 58-61 cm 22.5-24 inchadjustable Material: ABS polymer