Skid Lid Helmets - Size Chart
Helmet Size	Head Cir. (IN)	Head Cir. (CM)
XXXS	19-1/3 - 19-11/16	49 - 50
XXS	20-1/16 - 20-7/16	51 - 52
XS	20-7/8 - 21-1/4	53 - 54
S	21-5/8 - 22	55 - 56
M	22-7/16 - 22-13/16	57 - 58
L	23-1/4 - 23-5/8	59 - 60
XL	24 - 24-3/8	61 - 62
XXL	24-13/16 - 25-3/16	63 - 64