The men's Smartwool Classic Thermal Merino Baselayer 1/4 Zip Top offers a heavy baselayer solution to frigid temperatures. Rely on the 100% Merino wool construction for thermal regulation, moisture management and odor protection. The updated fit forms to your specific contour while flatlock seams and offset shoulders minimize chafing and enhance comfort under outer layers. Best worn for active days in the mountains whether you're skiing, hiking, biking, or running, this top is versatile enough to keep up with you. Upgrade your layering system with the consistent warmth of Smartwool's Classic Thermal Merino Baselayer 1/4 Zip Top for men.
Slim fit follows the body's contours for seamless layering
Merino wool offers moisture management, temperature regulation, and odor resistance
Flatlock seams, offset shoulders, and side seams minimize chafing and increase comfort
Quarter-zip design lets you control your temperature
Winter 2026/27 product
Smartwool Classic Thermal Merino Baselayer 1/4 Zip Top - Men's
