Neofleece Extreme Masque uses patented technology from Seirus Innovation Neofleece. Neofleece is an exclusive design created to be the warmest insulation on Earth. Neofleece uses a five layer defense to keep you warm: tough outer shell, DryHand waterproof/breathable liner, Neofleece (fleece lined neoprene), Thermolite synthetic down insulation, and wicking microfleece lining. The Extreme Masque was specifically designed for greater coverage over the ears and neck and dual adjustable Velcro closures allow the user to set how tight their mask is ensuring optimal comfort.