Features of the Smartwool Men's Merino 150 Baselayer Long Sleeve Top Raglan sleeve design elimates need for shoulder seams Flatlock seam construction designed to minimize chafing Breathable, soft, lightweight fabric offers next-to-skin comfort, moves sweat away from the body Merino fibers wrapped around a nylon core for added durability while still keeping the comfort of Merino next to skin Fabric Details 87% Merino Wool, 13% Nylon Core