Wigwam Minus 40C Silver Socks 75% Merino Wool, 15% Stretch Nylon, 7% Olefin, 2% Stretch Polyester, 1% Elastic (rubber) Wigwam's premiere cold weather boot sock - F2416 Minus 40 Degrees C Silver is made with wool yarn for warmth With SmartSilver protection your foot can stay free from odor Featuring a fortified foot bottom for longer wear, foot hugging fit, seamless toe closure and more you can't go wrong Get your self a pair of these fully cushioned socks that are great for any cold weather activity today!