SW001618 Smartwool Men's Performance Hike Full Cushion Crew The Hike Full Cushion Crew socks, formerly PhD Outdoor, use cushioning on the entire sock to help maximize warmth and protection. These responsibly sourced, ZQ-certified Merino wool hike socks are built with our top sock tech, including Indestructawool technology for enhanced durability, 4 Degree Elite Fit System for a dialed-in, performance-oriented fit, and Virtually Seamless toe for maximum in-shoe/boot comfort. Smartwool updated their hike line by improving mesh zones for additional breathability, as well as creating a new ply structure that reduces pilling while enhancing hand-feel and comfort. Not to mention, SW's best-feeling, best-fitting hiking socks are now made with recycled nylon-making these socks more sustainable than ever. Now that's something you can feel good in and about.