The Smartwool New Classic Rib Sock is a revived version of the Classic Rib. This medium cushioned crew sock offers wonderful stretch and luxurious feel with the soft Merino wool next to your skin. It provides a great fit and maximum comfort. It features ribbing that extends to toe and is made of 63% Merino Wool, 35% Nylon, and 2% Elastane. All Smartwool socks are proudly made in the USA, and carry a lifetime guarantee.