We've updated the fit of our Men'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 Classic Thermal Merino 1/4 Zip Features: 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