Lorpen Men's Insulator Socks 83% Acrylic, 8% Polyester, 7% Nylon, 2% Spandex Imported Super heavy full sock cushioning Knitting process allows more air pockets in the sock to trap the warmth and keep it next to the skin The thick looped cushioned thermal pile holds in the warm air The specially designed fibres act as insulation for maximum performance against the cold Mid-Calf height