Our warmest Capilene underwear. Expedition Weight is indispensable as a cold-weather base layer: It provides moisture-wicking warmth for stop-and-go activities. Worn alone, it is perfect for hiking and climbing at altitude. Please note: Expedition Weight underwear is sized for an against-the-skin fit; buy a size up if you intend to wear it as loose-fitting outerwear. Made in USA and imported.