Swiftwick Vibe Zero Socks With managed compression, Swiftwick Aspire One socks have been proven to reduce swelling, improve circulation and increase your endurance. They are crafted on a 200 needle machine for unrivaled comfort and fit. Moisture management wicks sweat away without the use of chemicals for a completely fresh and dry experience. Linked, seam-free toe. Synthetic, sculpted footbed and seamless toe assures maximum comfort and a blister-free environment. A lighter, thinner T-66 nylon Olefin material at the toe, heel, and foot bed for optimal airflow and targeted compression. A half-density weave allows for a stream-lined fit without bunching of fabric. Includes Swiftwicks Signature Double Welt Compression Cuff that wont fall down during movement. Made in USA.The only Nobel Prize winning fiber, these socks are constructed with 46% Olefin which retains less than .01% of its weight in moisture and resists deterioration from perspiration and detergents. Sizing Small: Men's 3-5½ / Women's 5-7½Medium: Men's 6-9½ / Women's 8-10Large: Men's 10-13 / Women's 10½-14U.S. shoe size equivalent.