We've updated the fit of our Men's Merino 250 Base Layer 1/4 Zip to improve functionality while also enhancing aesthetics. As one of our heaviest base layer tops and best base layers for cold weather, this garment uses 100% responsibly sourced Merino wool, shoulder panels, and a flatlock seam construction to help minimize chafing as well as help keep you comfortable and temperature regulated as you enjoy high-intensity skiing, hiking, running, and more. 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