FIT FOR COMPETITIONThe Nike Flyknit Racer Unisex Running Shoe provides an adaptive, lightweight fit with a racing-specific rubber outsole that delivers exceptional traction from your first to final mile. Lightweight Support A single-layer Flyknit upper wraps your foot in a second-skin fit for incredible, lightweight support.Adaptive Fit Dynamic Flywire technology adapts to your foot for a custom-like fit and secure lock-down.Ultimate Traction A Waffle rubber outsole with a diamond pattern designed specifically for racing delivers durable traction.More DetailsForefoot Nike Zoom Air unit for ultra-responsive cushioningFull-length Phylon midsole for lightweight comfortWeight: 170 grams approx. (men's size 9)Offset: 8mmNike Flyknit OriginsNike Flyknit technology was inspired by feedback from runners craving a shoe with the snug (and virtually unnoticed) fit of a sock. Nike embarked on a four-year mission with teams of programmers, engineers and designers to create the technology needed to make the knit upper with static properties for structure and durability. Then the precise placement of support, flexibility and breathability-all in one layer-was refined. The result is a featherweight, formfitting and virtually seamless upper.