Rubber sole Knit and synthetic leather upper features straight-edge cuts—meaning less waste. Originally designed for performance running, Max Air cushioning has just the right amount of support. Rubber Waffle outsole adds durable traction and heritage style. The upper is composed of 100% recycled polyester, while the outsole is made from 13% Nike Grind Rubber. Aggressive lines and paneling define the silhouette, underpinned by a foam midsole with an Air window in the heel. It's the perfect mix: a splash of heritage Nike running and a whole lot of comfort. The fast-paced look also includes a revamped Air unit window to energize your every step.