Our best selling base layer, Terramar Cloud Nine for women, is warm, lightweight, and incredibly comfortable. Using Thermoregulation comfort technology, the Cloud Nine keeps you feeling warm and dry in all conditions. The four-way stretch fabric (polyester and spandex) fits close to skin and allows full range of motion for even the most demanding activities. The Cloud Nine fabric also wicks moisture away from skin as you perspire, and dries extremely quickly so that you stay dry even as you sweat. Anti-microbial technology inhibits the growth of odor-causing bacteria, while the brushed surface provides extra warmth and comfort. Strategically placed mesh panels enable ventilation for optimal breathability, and flat-lock seams ensure no chafing. This is undoubtedly one of the best values in all of the base layer world!