The workhorse of the stability category, providing ample medial support for moderate over-pronators. The Structure keeps runners efficient through many different training volumes. - Dynamic Flywire integrates with the lacing system to wrap the mid-foot for a conforming, customized fit and superior lockdown. - Fly Mesh provides a tighter weave where more support and rigidity are needed and a looser weave where you need comfort, breathability and a conforming fit. - Triple-Density Midsole provides serious medial support for over-pronators. - Zoom Air in the forefoot for low profile responsive cushioning.