Ali Huang(TM) Adult Ajustable Bike helmets Mountain Bike Safety Hat Riding Bicycle Helmet and Equipment Ajustable with Snap on/off visor--with Multifunctional Cycle Head Wear As a Gift-The scarf is varied, not all the same as the picture Rashworthiness, not brittle to withstand the high intensity, strong foam density. Ultra-light, wind tunnel, duct design, effectively reduce 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 58-61cm and the head-width below 16cm Using one-piece construction and smooth tail lines not only stylish,more to reduce wind resistance.