WOW Youth Kids Motocross BMX MX ATV Dirt Bike Helmet Shark Red;

Helmet Size Chart

S 49-50 CM 19.3/19.7 Inch
M 51-52 CM 20.1/20.5 Inch
L 53-54 CM 20.9/21.3 Inch
Helmet Size Tips

(1)Wrap a measuring tape around your head about a half-inch above eyebrows
(2)Take measurement two to three times to pick the largest one.