The Nike Free RN 2018 PS 'Diffused Blue' has all the Dynamic Fit tech of the adult shoe, including a stretchy inner sleeve, heel strap and Flywire cables integrated with the laces for lightweight stability. This version has deep outsole sipes that are cut with a tri-star traction pattern for better splash down and lift off—while the ground-breaking flexibility stays intact—showing how far Nike Free has come since its original conception in 2004 by designers Tobie Hatfield and Eric Avar.