Smartwool Classic Thermal Merino Base Layer 1/4 Zip - Men's

2025 Smartwool Baselayer Top

We've updated the fit of our Men's Merino 250 Base Layer 1/4 Zip to improve functionality while also enhancing aesthetics. As one of our heaviest base layer tops and best base layers for cold weather, this garment uses 100% responsibly sourced Merino wool, shoulder panels, and a flatlock seam construction to help minimize chafing as well as help keep you comfortable and temperature regulated as you enjoy high-intensity skiing, hiking, running, and more.

Slim Fit
100% Merino wool fabric made with an interlock knit for enhanced comfort, breathability, thermoregulation, and odor resistance
Fit updated to improve functionality while enhancing aesthetics
Shoulder panels eliminate top shoulder seams

Flatlock seam construction designed to minimize chafing
10' (25 cm) center front zipper semi-locking slider
Knit in Vietnam: 100% Merino Wool. Exclusive Of Decoration
Garment Weight: 298 g = 10.51 oz
Style: SW016355