NIKE Free Hyperfeel Tr Men's Running Shoes Seamless upper design uses a one-piece Flyknit construction for superior support at a light weight Flywire cables incorporated in the lacing system for a supportive fit around the arch Lunarlon midsole provides cushion, flex and responsiveness Midsole wrap-up cradles your heel and midfoot to optimize multi-directional movement Nike Free Flex grooves promote a natural foot flex, simulating a barefoot feel