The Smartwool Men's Classic Hike Full Cushion Crew Sock is a merino wool sock for traditional comfort inside your boots. Slip on a pair of these old school cozies and each foot is surrounded with a full cushion blend of 56%; merino wool, 11%; nylon, 31%; recycled nylon, and 2%; elastane, knitted in the USA from imported yarn. The 4 Degree Elite Fit System ensures the sock stays in place, with a flex zone to maintain relaxed movement at the ankle. I recommend keeping up with your toenail trimmings, but there is a Shred Shield in place at the toe box to prevent wear and tear. Features of the Smartwool Men's Classic Hike Full Cushion Crew Sock Our first sock construction, only now featuring recycled nylon (content varies by style) Flat knit toe seam for additional comfort Elasticized arch brace for secure Fit Fabric Details 56% Merino Wool, 11% Nylon, 31% Recycled Nylon, 2% Elastane