The Smartwool 250 Baselayer Shirt just got a little more refined with an improved fit, chafe-free seam construction and panels that offer more comfort with a pack. This heavier, soft, 100% Merino wool fabric offers breathable warmth, moves sweat away from the body, and provides next-to-skin comfort in colder conditions. Features:Slim FitCrew neck with set-in sleevesShoulder panels eliminated top shoulder seamsFlatlock seam construction designed to minimize chafingConstructed of 100% Merino wool