2018 Nike Vaporfly 4% Flyknit Ekiden Running Shoes Womens 7 Mens 5.5 New White/Flash Crimson AJ3857-160 Four percent more efficient than Nike’s previous fastest marathon footwear, the 2017 Zoom Vaporfly 4% is upgraded with the debut of the Zoom Vaporfly 4% Flyknit sneaker in 'Flash Crimson.' Refreshed with increased lightweight flexibility and breathability, the runner is fitted with ultralight Flyknit mesh, stabilized by a full-length carbon plate an internal heel design. Energy-returning ZoomX foam cushions each step for a smooth ride. Built to meet the exacting needs of world-class marathoners. Designed for record-breaking speed. The Flyknit upper delivers breathable support, while the responsive foam and ful-lengthplate provides incredible energy return. Zoom X Technology New with box