Runner-informed data was used to create and place engineered mesh throughout the upper for lightweight and breathable durability. Extra padding at the collar helps keep your foot feeling comfortable. Additional support courtesy of a heel clip helps keep your foot feeling secure. The sole has a unique rocker design that's shaped for support during all 3 phases of your stride. It feels flexible when you push off the ground, has a smooth ride when your foot moves forward and cushions when you land. Nike React technology provides that soft yet responsive sensation at every step. The bottom is wider for more stability on contact. The rubber outsole keeps your feet to the ground with durable traction. Runner-informed data helped us create the heel, placing rubber where your foot needs it to help ensure a smooth transition from heel to toe.