I ordered the helmet in Gr. S, so to 58cm head circumference. -passte the first to carry the widest size level (adjustable in size) Just -after 2,3 times use the helmet has adapted perfectly to my head and now sits optimally (you get the feeling that he is still a bit "dilated" has) -Very light helmet -Blendeschutz (Sun) through the front plate -coole optics -good processing