At its core, the Structure Plus SP sneaker is built for runners who want stability without losing softness. Nike stacks Zoom X foam over React X foam — something they’ve never done in the Structure line before — and pairs it with a midfoot support system that wraps the heel and arch for a smoother, more controlled heel‑to‑toe transition. Engineered Mesh Uppers Zoom X & React X Cushioning Rubber Outsoles Padded Collar Lace Up Closure Nike Branding Style Code: IV4521-001