The Smartwool PhD Outdoor Light Mini Sock is a wool sock for your feet. Don't even try to put them on your hands. They're not mittens, people. The merino wool, nylon, and elastane blend provides moisture-wicking comfort for hiking, biking, even everyday life. Features of the Smartwool PhD Outdoor Light Mini Sock Indestructawool Technology Features a wool-based, patent-pending yarn and construction method for exceptional durability and comfort 4 Degree elite Fit system Uses two elastics for greater stretch and recovery to keep the sock in place Mesh zones designed for High-output activities or warmer temperatures provide ventilation Virtually Seamless toe Made in USA