Granvela BC012 Cycling Helmet, Lightweight Colorful Road/Mountain Helmet, Adults Adjustable Size Super fit engineering Suitable for people with head circumference between 56-62cm Use One Step technical material, EPS increases impact resistance of composite materials. It could safely protect your head when cycling Crashworthiness, not brittle to withstand the high intensity, strong foam density Ultra-light, 24 vents, duct design, effectively reduces wind resistance. High-quality foam layer, the adjustment within the twist, you can adjust the size of head circumference