Military Thermals supplies the highest quality 100% Polypropylene thermal garments, both imported and domestic. Military Thermals only sells 100% polypropylene thermal cold weather gear that is part of the Generation I Extended Cold Weather Clothing System (ECWCS) established by the U.S. Military. Why? There's nothing better and more economical. Don't be fooled by high priced, store bought brand names that cost three, four times as much, Military Thermals are the first choice of military personnel around the world and for good reason. Military Thermals retain more of your body heat than any other fabric. Polypropylene thermals are the best extreme cold weather base layer of clothing made.