Heat Holders Men's Thermal Bigfoot Socks Size 13-15 US Navy 91% Acrylic, 5% Nylon, 3% Polyester, 1% Elastane The ultimate in thermal socks, these Heat Holders have a massive tog rating of 2.34 keeping your feet fully insulated with the specially developed extra heavy bulk yarn. Seven times warmer than basic cotton socks The long pile cushioning, means these socks will not only help keep feet cosy but protected and supported too. Many More Styles, Colours & Sizes in Our Vast Range! Perfect for Winter