NIKE Free Flyknit + Womens Shoe Leather The FREE Flyknit offers a truly revolutionary fit. For optimal performance, we recommend a true-to-size fit, but personal preference may require you to move up a half size New standard in upper fit and performance: Enhances the natural motion features in the tooling for an even better and more natural ride Offers the runner an engineered, sock-like fit: Provides a seamless, ultra lightweight fit and feel Zones of compression and compliance specifically engineered: Delivers the perfect amount of tension and give in the upper for a perfect fit Runners can expect the upper to mold to the foot: Provides a compression, socklike fit unlike traditional footwear uppers