Stretch and support – flyknit constructed upper Lightweight, locked-down fit – flywire cables Flexibility – auxetic outsole with tri-star pattern Tough Injected unit sole (IU) foam Natural range of motion – rounded heel Take up the pace with the Free RN Flyknit 2017 Women’s Running Shoes from Nike. This running shoe delivers a comfortable Flyknit constructed upper and a tri-star outsole pattern that adjusts to your feet as they land. The Flyknit constructed upper delivers stretch and support and combines with the Flywire cables to provide a lightweight, locked-down fit. The auxetic outsole with its Tri-star pattern ensures flexibility. A tough injected unit sole (IU) foam doubles as an outsole and the rounded heel rolls with the ground to promote a more natural range of motion.