Helly's LIFA Merino Midweight collection is perfect for any type of cold weather activity. They combined a 100% merino wool layer with 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. 2-layer construction. 100% Merino wool exterior. Flat lock seams for ideal comfort and durability. Non-itch fabric. 57% Merino Wool/ 43% Polypropylene. Regular fit. Use wool detergent. Do not use fabric softener. Close zippers before washing. Wash inside out. Do not wring. Machine wash in lukewarm water - 40 C very gentle cycle. Do not bleach. Do not tumble dry. Do not iron. Do not dry clean.