Chaos Headwall Chimney Balaclava is the ultimate in cold weather protection designed to be worn with a helmet. It features a Polyester shell material that is coated with DWR treatment to make material highly water repellant. This hat is insulated with 70 grams of Thinsulate along with a high pile fleece to keep you warm in all conditions. The top of this hat is made from Chaos Pro Stretch fleece, which is extremely lightweight and warm when worn under helmet. the Flat lock seams on top of hat are comfortable when worn with helmet. Windproof material Front of the hat has ventilated panels with mesh lining and adjustable side panels for a secure & snug fit.