Z1R Jimmy Helmet Size:X Large Reverse coil zippers helps keep GSFLL3005 2XL Reverse coil zippers helps keep out dust and dirt With Heat Sealed Backing or Easy Sawing 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 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