The benchmark against which all others are judged, the 200 Oasis Long Sleeve Crewe is icebreaker's best-selling base layer-a versatile active top for year-round layering and everyday comfort. The soft, 100% merino jersey fabric is breathable, stretchy, and odor-resistant, and flatlock seams provide chafe-free comfort.Inspired by nature, icebreaker harnesses the performance qualities of natural fibers to offer an alternative to clothing based on petrochemical synthetics. Merino is an annually renewable fiber that naturally resists odors, keeps you cool when it's hot and warm when it's not, and lets your skin breathe for comfort all day, every day.