Sole material Rubber • Outer material PrimeKnit 360 Fabric • Closure type: Lace-Up • Dual-density Boost cushioning under arch • Fitcounter molded heel counter provides a natural fit that allows optimal movement of the Achilles • Adidas Primeknit upper wraps the foot in adaptive support and ultralight comfort; Engineered knit for enhanced breathability in key sweat zones • Ultraboost reinvented. These running shoes reboot key performance technologies to give you a confident and energy-filled run. The knit upper has a second-skin fit and is built with motion-weave technology for adaptive stretch and support. Dual-density cushioning delivers medial support and an energized ride.