heres thermal socks feature thermo-insulating technology that keeps heat close to the body. Merino wool socks are great for hiking skiing, camping, hunting, and many other outdoor activities. These hiking socks feature reinforced heel for added comfort and durability. Extra cushion on the bottom provides arch support. These wool hiking socks are made with 35% polyester, 35% cotton, 20% merino wool, 5% acrylic, and 5% spandex.