We've updated the fit of our Women's Classic Thermal Merino 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.Smartwool Womens Classic Thermal Merino Base Layer 1/4 Zip Features: Our slim fit is intended to follow the contours of the body Fabric helps combine the moisture management, temperature regulation, and odor resistance of 100% Merino wool with interlock knit for comfort Back body seam wraps to front Raglan sleeves Flatlock seam construction designed to help increase comfort and minimize chafing Size medium center-front zipper: 8" (20 cm) 100% Merino wool