With supportive cushioning built for a smooth run, the Nike InfinityRN 4 is a brand-new take on a familiar favorite. It's made from our all-new Nike ReactX foam, which gives you 13% more energy return compared with Nike React foam, to help you stay fresh and bouncy. (What's more? Nike ReactX reduces its carbon footprint in a pair of midsoles by at least 43% compared to Nike React foam.*) We coupled the ReactX foam with Nike Running's best-fitting Flyknit yet, so you can take off anytime, anywhere with secure upper support and breathability. It’s the kind of shoe that can grant you that priceless peace of mind to go faster and farther thanks to an intuitive design that supports every stride. *The carbon footprint of ReactX is based on cradle-to-gate assessment reviewed by PRé Sustainability B.V and Intertek China. Other midsole components such as airbags, plates or other foam formulations were not considered.