The Nike Free 5.0 v4 running shoe features an all no-sew upper design that's engineered to conform to the foot even better. Super breathable, very lightweight mesh upper. Proven and tested Phylite? midsole features an engineered pattern of longitudinal and latitudinal sipes that produces a naturally efficient footstrike. BRS 1000? rubber inserts in the outsole enhance durability at high-wear zones.