100% Washable Merino Wool, 19.5 micronOur signature wool, Merino 100™ actively adjusts its microclimate according to body temperature, keeping you warm in colder temps and cooler as it heats up. It's exceptionally comfortable, wicks moisture under any conditions, and naturally neutralizes odors. The "Total Easy Care" tag means you can machine wash it as necessary without worrying about shrinkage or lost shape.