The Smartwool Men's Merino 250 Base Layer Colorblock Crew Shirt gives you a great feel for winter. It features 100% responsibly sourced Merino wool made with an interlock knit for enhanced comfort, breathability, thermoregulation, and odor resistance. With shoulder panels and a flatlock seam construction, this base layer brings consistent comfort, as well as reliable warmth and durability, to winter hiking, running, and skiing.