Featuring cushioning throughout for warmth and engineered advanced zonal padding system for support and comfort, this is the ultimate sock for long or multiday high mountain and winter expeditions. Merino Performance Fusion Technology provides resilient padding, balanced insulation, moisture wicking and outstanding durability for all day comfort. The Performance Fit is close and supportive and won’t slip down, or bunch in your footwear no matter how long the day. The toe box is closed with an insulated Flat Toe Seam to prevent cold spots and the sock is kept securely in place with an Elasticated Arch and 3D-shaped heel cup.