Design: New internal Flyknit fit band offers elastic, secure support Water-repellent liner in the toe helps keep you dry when the weather turns Curved outsole helps your foot rock smoothly from heel to toe and through your stride to foot strike ReactX foam reduces the carbon footprint of the midsole by at least 43% compared to prior Nike® React foam Snug fit; Nike® recommends ordering a half-size up In-Shoe Comfort: Flyknit tongue is adjustable and plush Foam collar is soft and supportive to the touch More room in the toe box adds comfort ReactX foam gives you an incredibly smooth feeling, helping you push your limits ReactX foam delivers +13% energy return compared to React foam, helping you stay fresh and bouncy during your run Durability & Traction: Waffle outsole provides durable traction