Features of the Smartwool Women's Merino 150 Baselayer Bottom Merino-lined, 1.5in. (4 cm) wide elastic waistband designed for maximum comfort 100% Merino next to skin Stretch merrow stitching designed to elevate comfort, range of motion, and Fit 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