NIKE Men's Free 5.0 Volt/Black/Elctrc Green/Pht Bl Running Shoe 12 Men US Synthetic-And-Mesh Flywire technology for ultra-lightweight support Nike Free Phylite midsole doubles as an outsole for lightweight cushioning, durability and reduced weight Deep hexagonal flex grooves for a natural, barefoot-like ride No-sew overlays throughout provide support and durability without added weight