Engineered for marathon performance, these sneakers feature three innovative technologies for a propulsive ride. Dual Air Zoom units combine with a full-length carbon fiber plate to assist with energy return, while the Zoom X foam midsole provides comfort throughout the race. two forefoot Air Zoom units ultralight Zoom X foam midsole wider carbon fiber Flyplate Atomknit upper multidirectional containment and breathability notched laces integrated knit tongue with lofted padding fits small, recommend ordering a half size up