Good to Know: The more you run or walk, the more room you need. On trainers and boots are typically designed narrower in the heel and tongue; please consider going up a size if you have wide feet. Ideal for 5ks, short-medium runs and road running Helion superfoam enhances the Cloudswift's energy return and durability on the road Breathable engineered-mesh allows to foot to flex naturally and reduces moisture build-up Durable rubber reinforcements provide high traction at high speed, even on wet roads The shoe to run the city. The city is a tough place to run. So On has made the Cloudswift tougher. With CloudTec in Helion superfoam, it's made to perform on hard surfaces and protect from impact. This is cushioning without compromise - with an engineered upper to match. From a swift 5k at lunchtime to a cross-town commute or the longer Sunday run, you'll feel the difference when you hit the streets in the Cloudswift. Helion Superfoam CloudTec in Helion superfoam gives the Cloudswift cushioning with zero compromises. Engineered for urban running, Helion is light on weight but big on energy return and durability. Temperature resistant, it provides the same unrivalled performance in hot and cold conditions and durable rubber reinforcements provide high traction at high speed, even on wet roads. Urban Upper The breathable engineered-mesh of the inner sock construction keeps your feet cool, even when on-the-road temperatures soar. Strong yet stretchable, the TPU mechanical sideband delivers gentle midfoot support during swift city sprints. It also gives you a hiding place to stash your laces.