Champion Duofold Varitherm Men's Base-Layer Thermal Pants Mid-weight 5.5-oz. quick-drying 96% polyester/4% spandex jersey with 360-degree stretch. Performance benefits last the life of the garment: Will not wash or wear out. Importado 36-degree stretch gives you maximum ease of movement. 36-degree stretch gives you maximum ease of movement. Tag-free crewneck  no scratch, no inch. Flat-locked seams for non-chafe comfort. Great on its own or as base-layer thermal underwear.