The AUTHENTIC WOOL PLUS two layer garment has been specifically engineered with our COLDPRUF® Insulation System to trap air between the layers of fabric to provide anatural 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.