We've put all of our smarts into these new and improved Women's PhD Run Ultra Light Striped Micro socks. You won't break your stride, thanks to our Indestructawool technology designed for added durability and an Achilles tab designed to help prevent sock slippage. And by adding our brand-new Shred Shield technology to some of our best running socks, the wear and tear from toes is reduced, helping you push toward your finish line and achieve higher mileage.. . . . . PhD is Built for Performance in the Highest Degree. Women's specific fit; narrower heel and slimmer fit. 4 Degree Elite Fit System for a dialed, performance-oriented fit with flex zone at ankle joint. Indestructawool technology features a patent-pending construction method for exceptional durability and comfort. Mesh ventilation zones provide optimum moisture management and maximum breathability. Ultra Light Cushion is non-cushioned for maximum performance in close-fitting shoes. Shred Shield helps reduce wear from toes. Sock Height: Micro. Virtually Seamless(TM) toe for enhanced comfort. Achilles tab designed to prevent sock from slipping down into footwear. 49% Merino Wool, 47% Nylon, 4% Elastane. Machine Wash Warm, Wash Inside Out.. Made in USA of Imported Yarns.