Meet the better-than-ever Smartwool Men's Classic Thermal Merino Base Layer Crew. Smartwool updated this 100% Merino wool fan-favorite with a new fit to improve functionality while enhancing aesthetics. Shoulder panels eliminate top shoulder seams and a flatlock seam construction helps prevent chafing. Add one of Smartwool's best base layers for cold weather to your winter wardrobe and experience the difference the next time you go skiing, hiking, climbing or biking.