Engineered for marathon performance, this design features three innovative technologies to enhance speed. Double Air Zoom units combine with a full-length carbon fiber plate to provide a propulsive feel, while the Zoom X foam midsole offers responsiveness. 2 forefoot zoom air units zoomx foam midsole full-length carbon fiber flyplate atomknit upper wider carbon fiber flyplate integrated knit tongue with lofted padding 8mm heel-to-toe drop runs small, recommend sizing up