The OS1st Merino Wool Plantar Fasciitis socks are crafted with 100% Recycled Merino Wool and Ultra-Soft Nylon to give you natural moisture-wicking and increased temperature regulation. Combined with our patented Compression Zone Technology specially designed to target Plantar Fasciitis, makes this a must-have for your sock drawer; Keeping your feet warm and cozy while fighting plantar fasciitis.