Size M (55-56 CM,21.7/22.0 Inch); the helmet comes with one installed tinted shield; one extra spare clear shield and one anti fog film; Advance Aerodynamics Design & Quick Release Buckle Design; Light Weight Durable Aerodynamic Thermoplastic Alloy Shell Beautiful Glossy UV Protective Finish Removable and Washable Padding; DOT Approved; Meets Federal Motor Vehicle Safety Standard 218 (FMVSS 218); Helmet Size Chart
S 53-54 CM 20.9/21.3 Inch
M 55-56 CM 21.7/22.0 Inch
L 57-58 CM 22.4/22.8 Inch
XL 59-60 CM 23.2/23.6 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.
S 53-54 CM 20.9/21.3 Inch
M 55-56 CM 21.7/22.0 Inch
L 57-58 CM 22.4/22.8 Inch
XL 59-60 CM 23.2/23.6 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.