Enjoy streamlined comfort while hiking, biking or playing sports; or use as a light, layering piece under your uniform any time. Features Aegis Microbe Shield, today's most advanced antimicrobial technology that prevents the growth of odor-causing bacteria. Complete moisture management--wicks perspiration away from body, toward surface of garment for quick evaporation, keeping you cool when it's hot, and dry when it's cold. Soft, breathable, and ultra-lightweight 100% polyester fabric.