Type: Running Weight: approx. 5.6 oz. Upper: Flyknit constructed upper delivers zoned stretch and support. Flywire technology woven into the upper integrates with the laces for a dynamic, supportive fit through the midfoot. Midsole: Dual density,Low-profile injected unit sole (IU) foam provides a resilient ride and is tough enough to double as an outsole. Outsole: Tri-star,auxetic outsole pattern expands with your step to provide flexible cushioning.