Duofold by Champion Varitherm Men's Long-Sleeve Thermal Shirt_Black_L Expedition-weight 9.4-oz. 2-layer 96% polyester/4% spandex with quick-drying moisture control and 360-degree stretch Importado Expedition-weight 9.4-oz. 2-layer 96% polyester/4% spandex with quick-drying moisture control and 360-degree stretch Great on its own or asbase-layer thermal underwear. Sleek expedition-weight fabric traps warmth between two thermal layers. Plus, it wicks sweat from your skin, dries quickly for chafe-free comfort, even resists garment odors. 360-degree stretch allows maximum ease of movement. Drop-tail hem provides extra coverage.