At sixthreezero, we take fit, safety, and style seriously. Take your rides to the next level with the sixthreezero Unisex Helmet. Our lightweight cycle helmet includes a full-coverage, shock-absorbent ABS shell for outstanding protection. Ride safely and comfortably without compromising style. The eight flow ventilation system and visor feature keep you cool, even on the toughest rides. Sleek and smooth straps are easily adjustable to tailor your fit and maximize security. Size medium is recommended for riders 8+ and measures 21.6-22.8 inches in circumference. Size Large is recommended for riders 15+ and measures 23-24.5 inches in circumference.