The Women's Helly Hansen Lifa Merino Lightweight Crew Baselayer is versatile and ideal for all cold weather activities. Using their proven 2-in-1 layer system, Helly have combined LIFA® Stay Warm moisture management and the natural warmth of merino in an extremely lightweight crew. LIFA® Merino LIGHTWEIGHT delivers all the great benefits of merino wool fibers plus the unique wicking properties of technical LIFA® fibers.