Smartwool Merino thermal sweatshirt 1/4 zip Classic Intraknit

We have updated the fit of our men's Classic Intraknit thermal base layer 1/4 Zip to improve functionality while enhancing the look. As one of our thickest base layer tops and one of the best base layers for cold weather, this garment uses 100% responsibly sourced merino wool, shoulder panels, and flatlock seam construction to help minimize friction while keeping you comfortable and at a regulated temperature as you enjoy skiing, hiking, running, and more.