The men’s MERINO 150 BASELAYER PATTERN Long Sleeve is a premium all-season adventure shirt, perfect for summer hiking and as a first winter layer. This body temp regulating long-sleeve t-shirt features the properties and breathability of Smartwool merino wool. Core Spun technology wraps merino around a nylon core for added durability while keeping comfort next-to-your-skin. Smooth flatlock seams minimize chafing along with offset shoulder and side seams. The Merino 150 Pattern Long Sleeve performs well on its own in warmer temps while layering perfectly in colder climates.