Nike Women's Free Flyknit 4.0Constructed with an ultra comfortable one piece Flyknit upper, the Nike Free Flyknit 4.0 is lightweight, flexible, and supportive. This advanced running sneaker also boasts knit-in Flywire cables that wraparound the midfoot, knit-in heel support, slim midsole, asymmetrical lacing, and hexagonal flex grooves on the outsole with secondary cuts for excellent flexibility.