Chaos adult motocross crash helmet blueconforming to the strictest of safety standards, not only are these helmets protective but they're also attractive'. '.strtoupper('w')ith the latest chaos graphics this collection is available in four different colour options.chaos adult motocross helmetpolycarbonate constructionacu ec22 05 approvedlightweight helmetroad and race legalthe item comes with a free helmet protective bag so you can store your helmet safely keeping it in the best possibly condition.what size am i?it's easy to find the helmet size to fit you'. '.strtoupper('b')ike helmets should fit snugly on your head even if you've got big hair'. '.strtoupper('i')deally pressure should feel firm and even all over.to find the right helmet size, measure all the way around your head at the widest part from the front of your forehead right around the back of your head and back to the front again, keep the tape measure above your ears and make sure it feels firm but not overtight or too loose all our helmet measurements are in centimetres cms.