Synthetic sole Weight: approx. 8.8 oz. Upper: Single layer engineered mesh with internal, seamless notched inner sleeve for maximum comfort coupled with Dynamic Flywire technology for maximum lockdown. Bottom eyelet has been moved up to open up the forefoot flex zone and provide an optimal fit. Midsole: Full-length Cushlon ST foam works with a Nike Zoom unit in the heel for soft, responsive cushioning and great forefoot flexibility. Beveled heel. Outsole: Environmentally preferred solid rubber with classic Waffle outsole for durable traction. Lateral rubber blades for added sensory feedback and cushioning.