Mesh,Nylon,Wool Made in USA Jump into the sweater weather season with the Smartwool? PhD Outdoor Light Micro 3-Pack of socks! Sold as a three-pair pack. Micro length offers a low-cut wear. WOW technology in High Density Impact Zones (forefoot/heel) to reduce shock and abrasion. Wool on Wool (WOW) technology adds an additional layer of 100% SmartWool? Duroyarn? to give the PhD sock line up to 30% more durability, performance and comfort. 4-Degree Banded Fit System construction for performance fit. SmartWool? infused for moisture, temperature and odor control. Duroyarn? reinforcement for added comfort and durability. Arch band at upper and lower instep for support. Reinforced heel and toe. Strategic Mesh Zones for maximum ventilation. 60% wool, 38% nylon, 2% elastane Machine wash, line dry. Made in the USA.