Originally adopted for use by the U.S. military, including the Special Operations Forces, Extended Cold Weather Clothing System (E.C.W.C.S.) Polartec Power Dry is exceptionally effective at wicking moisture away from the skin. All three weights use a dual-surface system with a tough outer layer for rapid dissipation of sweat that has been drawn away from the skin by the inner layer. This leaves a soft, dry surface next to your skin. And because layering is an essential part of cold-weather protection, the outer fabric is smooth-faced, so other layers slip on easily. Wear the light Tech Silk-Weight model in cool to moderately cold weather. Medium Weight offers versatility to cover a variety of activities in fluctuating temperatures. Our Polar Weight delivers incredible warmth with minimal weight. All three weights incorporate a high-loft grid channel back for enhanced breathability and superior moisture wicking. Offers even greater compression than conventional fleece for easier packing. Imported.