Women's best-in-class running shoes built for maximum comfort and energy return on all types of runs Sock-like fit hugs the foot; Boost midsole for responsive energy return Stretchweb outsole flexes naturally for an energized ride, and Continental Rubber gives you superior traction This product is made with Primeblue, a high-performance recycled material made in part with Parley Ocean Plastic. 50% of the upper is textile, 75% of the textile is Primeblue yarn. No virgin polyester.