Rubber sole Style#: CD4372-012 Higher foam stack heights provide a softer feel. A wider shape provides a more stable ride, helping release energy with every step. The shape of the Nike React foam midsole is all about zonal performance, providing support for the 3 phases of a runner's stride—flexibility at toe-off, a smooth ride at mid-stance and cushioning at contact. Less material in the shoe means you're closer to the foam, creating a softer, more responsive experience. Increased rubber at the outsole helps deliver traction and durability. The Nike React Infinity Run Flyknit is designed to help reduce injury and keep you on the run.