Crashworthiness, not brittle to withstand the high intensity, strong foam density. * Use ONE STEP technical material, EPS increases impact resistance of composite materials. * Ultra-light, wind tunnel, duct design, effectively reduces wind resistance. * High-quality foam layer, the adjustment within the twist, you can adjust the size of head circumference. * Suitable for people with head circumference 54-65cm and the head-width below 16cm.