Lightweight enough to roll up and carry in a jacket pocket this ussen flight hat is effective and convenient thermal layering headwear designed to be used on its own or under a helmet this double layered woven polypropylene thermal hat has very fast wicking properties with a long turn up that can be pulled right down over your ears and back of your neck in colder conditions this british made hat is part of the ussen range of thermal layering clothing including multitube neck gaiter therm