Indestructawool technology for enhanced durability 4 Degree elite fit system for a dialed-in, performance-oriented fit Shred Shield technology reduces wear from toes Smartwool running socks belong to our collection of our Performance socks, a tier that encompasses socks designed specifically to perform during activities like hiking, skiing, running, and cycling. This will also feature Athlete Edition socks for specialized activities like ultrarunning, ski racing, and so on. Designed for athletes, our Run socks represent the highest degree of performance, leveraging decades of sock-making expertise. These durable socks feature additional technologies like IndestructawoolTM, a patent-pending Merino wool based durability construction, and our 4 DegreeTM elite fit system for maximum in-shoe comfort. Wear these running socks on your next marathon, sprint competition, hiking excursion and more. Taking the day off? These supportive athletic socks are made for casual activities too, such as walking in the park or playing with family and friends. They can even be worn to work if you like to stay nimble around the office. Simply put, these socks will be a clothing favorite. Put a pair on, and go see what you can do.