U.S. Military Surplus Fortiflame® Layer 4 ECW Pants. The latest evolution by legendary United Joint Forces provides maximum comfort in extreme cold-weather conditions. 8-oz. jersey knit blend has natural stretch and a soft fabric face for the ultimate next-to-skin comfort. Fortiflame® fabric is inherently flame resistant and has "0" after-flame or melt/drip during test method ASTM D6413-11. Unique moisture-wicking technology lifts sweat to the surface for quick-drying evaporation. Treated with an antimicrobial to resist odors. The official version used as part of the U.S. military cold-weather uniform. Made to strict military specs for years of dependable use.