Wigwam 40 Below Cold Weather Socks in Grey Twist are made in USA of 49% wool for durability, resiliency, and warmth, 51% nylon for durability. These 40 below socks are fully cushioned for extra warmth and comfort with an ankle hugging rib. This design, fibers and construction meet the critical needs of the active outdoor sportsman who want a good fit while on the trails or on the job. Sizes:Sizes:Medium - Large - Extra Large