nike free run+ running shoes,Off-center lacing and full innersleeve add plush comfort.It has a multi-layer upper and breathable mesh that maintain lightweight, second-skin-like fit .Removable insole.technology include :Sculpted Phylite?, BRS 1000? ,Waffle? piston outsole.As this shoe allows the muscles in the foot to gain strength by providing less constriction, runners are advised to gradually break into the shoe rather than immediately running long distances as to prevent muscle cramps and other discomforts, such as the notorious shin splints,nike Running Shoes,descript from http://www.freerun-shoes.com