The Nike Dual Fusion Run 3 is an excellently designed shoe and has some great features that are commonly sought after by both avid runners and those that run more leisurely,but they are not for everyone.The upper design has been completely refreshed vs last year. Single layer mesh, inner sleeve, welded synthetic overlays upper.Two different densities of EVA injection stacked over each other in the midsole.Some welded overlays help with providing structural support.