Flyknit upper creates a barely-there feel that promotes natural movement. Drop-in midsole is firmer in the heel for stability, yet softer and more flexible in the forefoot to provide comfort. Firm rubber in the heel provides durability and a stable feel for high-intensity intervals. Heel clip on the rear sides of the shoe help minimize drag during wall exercises and handstand pushups. Rear foot stability in the form of a heel counter. Flywire technology integrated into laces near the midfoot to help keep your foot locked-down. TPU overlay provides durability in high-wear areas throughout the shoe.