For Summer 2014, Nike introduces the latest edition of its Free 4.0 Flyknit trainer. More flexible than the 5.0 and more cushioned than the 3.0, the Free 4.0 Flyknit features a lightweight, supportive one-piece Flyknit upper made entirely of polyester yarn, and a highly flexible, low-profile outsole. With a 6mm difference between heel and forefoot height, the Free 4.0 Flyknit gets you closer to the ground for a more natural feel while still offering a great blend of cushioning and support. The Summer 2014 colorways of the Nike Free 4.0 Flyknit are now available at the brand’s online store for $120 USD each.