GT helmet M3

Size Head circumference (cm) Head circumference (inches)
XS 53 - 54 cm 20¾ - 21¼ inches
S 54 - 56 cm 21¼ - 22 inches
M 56 - 57 cm 22 - 22½ inches
L 57 - 59 cm 22½ - 23¼ inches
XL 59 - 60 cm 23¼ - 23¾ inches
XXL 60 - 62 cm 23¾ - 24½ inches