This innovative running shoe gets structure and support from Nike Flyknit. The result? An incredibly lightweight shoe with a second-skin fit to take you across the finish at a record pace. One-piece knit upper seamlessly integrates areas of high support, stretch, and breathability where you need them most without adding weight. Lightweight Flywire wraps the foot and is adjustable through the laces, providing a customized fit. Full-length Phylon with a Zoom Air unit for lightweight, responsive cushioning. Waffle skin rubber in the outsole features a racing-specific diamond pattern for lightweight durability and traction. Wt. 6.2 oz.