Smartwool Classic Thermal Merino Baselayer 1/4 Zip Women'sThe Smartwool Classic Thermal Merino Base Layer 1 4 Zip for Women has been updated to improve functionality while also enhancing aesthetics. One of the heaviest Smartwool base layer tops, and one of their 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 keep you comfortable and temperature regulated as you enjoy high