The Nike Free 3.0 v4 is a minimal running shoe that blends the strengthening and injury-prevention benefits of barefoot running with the comfort and protection of a shoe. Nanoply engineered suede composite upper is laser perforated in strategic zonal areas of upper to provide adaptive fit. Seamless innersleeve tongue construction. Off-set 17/13mm heel to forefoot drop. Transtarsal hot knife sipes offer natural motion flexibility. IU midsole foam adds lightweight durability. BRS 1000™ carbon rubber and environmentally-preferred rubber inserts enhance durability at high-wear zones. Non-removable insole. Wt. 5.5 oz.