The Tundra Aerogel Balaclava celebrates the insulation trusted and tested by NASA with PrimaLoft® Aerogel: The world's - and as far as we know, space's - most reliable warmth. A polyester crown, windproof construction, and strategically placed Aerogel insulation add durable warmth where you're most susceptible to frostbite; along the cheeks, over the nose, and under your eyes. Over-the-mouth neoprene blocks wind while providing stretch and insulation, and venting around the mouth allows condensation to escape so your goggles won't fog up.