The ultralight Cloudboom Echo combines a carbon Speedboard with an extreme rocker shape to give every step an extra powerful kick. Add the minimalist upper and enhanced forefoot cushioning and you're ready to crush records in complete comfort. Every element is engineered for performance.The 100% recycled polyester engineered mesh upper delivers 100% performance. Targeted reinforcements ensure ventilation and hold for sharp turns. In the outsole, the rubber compound in specific geometry increases ground contact area for maximum efficiency even in wet conditions.More speed, More energy return, More comfort. The Cloudboom Echo is on-Running's fastest-ever marathon shoe. Developed with their fastest runners, designed with on's lightest materials. Less weight and more performance. Fantastic cushioning but still with the ability to handle sharp turns at speed on asphalt. This extremely agile shoe has a single layer of ultralight engineered mesh in the upper that gives maximum breathability and keeps the temperature down. The forefoot has been reinforced for stability on any sharp changes in direction and a new traction pattern on the sole makes it unstoppable, even in wet conditions. To put it simply, the Cloudboom Echo has everything you need for your fastest race ever. Get ready to blow your PB. to pieces. Boom by name, boom by nature!