The Nike Wmns Free 4.0 Flyknit is an advanced running sneaker inspired by foot anatomy and engineering a barefoot feeling shoe. With a speckled, one-piece upper, this 'Glacier Ice' women's option boasts a Flywire lacing system that wraps around the midfoot, integrated heel support and a breathable vamp. Lightweight Phylite midsole cushioning yields responsiveness over a rubber outsole with hexagonal flex grooves and secondary pistons.