3WF1011 On Running Women's Cloudswift 4 The iconic road runner gets a performance upgrade. Featuring a new dual-density midsole for softer landings and more powerful take-offs. Plus, a breathable flat-knit upper and cage construction, for secure foot lockdown and a fresh aesthetic. Speedboard: Injection molded nylon-blend Speedboard for an energetic and responsive ride. Upper: Made using a single piece of flat-knit engineered mesh, the breathable upper has a snug, sock-like fit that adapts to a wide range of foot shapes. Midsole: new dual-density midsole is made with two types of Helion superfoam – for soft landings and powerful take-offs. Perforated toe box Updated cage construction for better midfoot lockdown Rocker geometry for a forward-rolling sensation