Size chart:
S 55 cm 38 cm 33 cm 1-3 Years
M 60 cm 42 cm 36 cm 2-4 Years
L 70 cm 44 cm 42 cm 3-6 Years
XL 75 cm 48 cm 46 cm 5-8 Years
XXL 80 cm 52 cm 50 cm 7-10 Years