Crafted with 100% responsibly sourced Merino wool using an interlock knit, the SmartWool Men's Classic Thermal Colorblock Baselayer Crew guarantees maximum comfort, breathability, thermoregulation, and odor resistance. Its shoulder panels and flatlock seam construction ensure reliable warmth and durability for winter activities like hiking, running, and skiing. Additional features include a shoulder panel design to eliminate top shoulder seams and a flatlock seam construction to minimize chafing. Made with 100% Merino wool, exclusive of decoration, this baselayer is perfect for outdoor enthusiasts.