Fit and Design: 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 Go Far. Feel Good.(TM) Guarantee Technology: Merino 250 fabric offers breathable warmth, moves sweat away from the body, and provides next-to-skin comfort in colder conditions Additional Details: Weight: 276g / 9.74oz