Z1R Jimmy Helmet Size_24 How It FitsPortland made 503 Color Deep Gray How It FitsPortland made 503 last has a casual fit without compromising Danner's comfortable lace to toe construction Comfortable micro fleece lining at collar SIZE HAT HEAD(CM) HEAD(IN) Medium 7 1 8 7 1 4 57 58 22 3 8 22 3 4 Large 7 3 8 7 1 2 59 60 23 1 8 23 1 2 X Large 7 5 8 7 3 4 61 62 24 24 3 8 2X Large 7 7 8 8 63 64 24 3 4 25 1 8 Advanced abs polycarbonate alloy shell passes DOT standardsDual forehead vents are closable and direct air into the helmetComfortable brushed nylon interior with padded chinstrap3 snap removable bubble visor5 snap shell design will accept most face shields (not included)Spacious ear pockets for accepting speakers Z1R HELMET SIZING CHART