Product descriptionHELLY HANSEN say...We combined a 100% merino wool layer with our proven LIFA® fiber technology in a 2-layer construction. This LIFA® Merino Midweight layer delivers all the breathable, natural warmth of merino wool, plus the unique moisture management properties of LIFA® fibers. Helly Hansen Lifa Merino Midweight 1/2 Zip Black