1000 Mile Men's Fusion Merino Walking Sock Outer Layer - 40% Merino Wool Double layer construction: eliminates friction between foot and shoe, reducing wear and preventing blisters. Tactel inner layer: wicks away perspiration to keep feet dry and cool. Padded comfort zones: padding on the toe, heel and ball area of the foot for extra comfort and protection. Achilles Tendon protection: full length padded protection for the Achilles Tendon - the first sock to offer you this Arch bracing: for additional support. Outer Layer: 40% Merino Wool, 29% Nylon, 23% Polyester, 6% Cotton and 2% Lycra, Inner Layer - 1000 Tactel