The AUTHENTIC two layer garment has been specifically engineered with our ColdPruf Insulation System to trap air between the layers of fabric to provide a natural warmth shield. The Outer Layer of MERINO WOOL, nature's warmest fiber, blended with Combed Ring Spun Cotton and Nylon and paired with 100%Combed Ring Spun Cotton on the Inside, offers the desired WARMTH and COMFORT in very cold to extremely cold weather conditions during low to medium activity. THE AUTHENTIC - NATURAL WARMTH AND COMFORT.