The Beanie hat will effectively protect your head on cold and windy days. The specific construction for each area optimises thermal insulation and moisture regulation. Fitted seamless design. Side vents allow for comfortable wear under a helmet without discomfort. Materials: 100% Polyester. Size M-L for head circumference of 56 to 59 cm. Size L-XL for head circumference of 59 to 63 cm. Weight: 25 g in size M-L.