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 Fit & Design: Slim fit intended to follow the contours of your body Fabric helps combine the moisture management, temperature regulation, and odor resistance of 100% Merino wool with interlock knit for comfort Flatlock seam construction and offset shoulder and side seams designed to help increase comfort and minimize chafing Side seams wrap to front