RaceQuip 274993 SportMod Flat Black Medium SA-2010 Full Face Helmet Exceeds Snell SA-2010 rating Hand laid fiber glass shell Expanded polystyrene (EPS) liner Comfort fit blended Nomex interior Distortion free 3 millimeter polycarbonate low fog shield; helmet dimensions: 7-1/8 to 7-1/4 (22-3/8 inch to 22-7/8 inch circumference)