The Smartwool Men's Classic Thermal Merino Base Layer Colorblock Crew Shirt is a midweight thermal base layer designed to deliver dependable warmth and comfort through every cold weather adventure. Made from 100% ZQ Merino wool, it naturally manages moisture, regulates body temperature, and resists odors to help him stay comfortable from first tracks to the final mile. The slim fit layers easily beneath outerwear while soft interlock knit fabric provides exceptional next-to-skin comfort. Flatlock seams and offset shoulder and side seams minimize chafing, making it ideal for skiing, hiking, running, and winter training. Built for reliable performance and lasting durability, this crew shirt is a go-to layer whenever temperatures begin to drop.