A year-round favorite, the Classic All Season Merino Baselayer Long Sleeve work hard to keep you comfortable everywhere from the ski hill to the campsite. Ultra-smooth Merino helps regulate body temperature, breathes well and naturally resists odors. What else do you need in a baselayer? How about smooth flatlock seams to help minimize chafing. Featuring Core Spun technology, we've wrapped Merino around a nylon core for added durability while still keeping the comfort of ultra-soft Merino next to skin.