We've updated the fit of our classic Women's Merino 1/4 Zip Thermal Base Layer to improve functionality while elevating aesthetics. As one of our heaviest base layers and one of our best cold-weather base layers, this garment uses 100% responsibly sourced Merino wool, shoulder panels, and flatlock seam construction to help prevent chafing and keep you comfortable and temperature regulated while you're skiing, hiking, running, and more.