These Peakheat work socks use a unique yarn blend of Merino wool and ThermoliteA(R) to keep your feet warm during the coldest days without the bulk. Not only are they warm but also built tough for long lasting wear. a Unisex fit a Reinforced Heel/Toe a Shock Absorption a Comfort Toe Seam a Arch Support a Breathable Mesh a Moisture Wicking a Memory Knit a 39% Merino wool, 32% Nylon, 22% ThermoliteA(R), 5% polyester, 2% spandex a Style 6631