Nike Free 3.0 v4 Running Shoes

A seamless, ultra-thin upper material called NanoPly covers most of the stretch mesh upper, providing additional structure in key areas. Even though the v4 has tighter gaps between the siping of its platform, it improves on the flexibility of the prior Free 3.0 with the addition of a Transtarsal Flex Groove that runs the length of the shoe. Nike lowered the heel-to-toe drop of the Free 3.0 v4 by raising up the forefoot stack height by 3mm.