Details: Lightweight and flexible, the Nike Flex RN 2017 enhances your natural stride for a more comfortable, efficient run. One-piece engineered mesh upper for a breathable, lightweight fit. Dynamic Flywire cables wrap the midfoot for adjustable lockdown through the laces. Soft Phylon foam within a firm carrier combines comfort and durability for a smooth ride, mile after mile. Tri-star outsole pattern flexes with the foot, allowing a natural range of motion throughout your stride. Wt. 8.1 oz.