LIGHT FOR FLIGHTThe innovative Nike Flyknit Racer Unisex Running Shoe (Men's Sizing) gets its structure and support from Nike Flyknit technology. As a result, it's incredibly lightweight, with a precision fit that feels like a second skin. It's no wonder the world's best marathon runners are wearing it in competition.Available in men's sizes. Reference the Size Chart above to convert a women's size to men's. BenefitsKnit upper for breathability and supportForefoot Nike Zoom unit and full-length Phylon midsole for lightweight, responsive cushioningWaffleskin rubber outsole with racing-specific diamond pattern for lightweight durability and tractionWeight: 5.6 ounces (men's size 9)Targeted SupportThe one-piece knit upper of the Nike Flyknit Racer seamlessly integrates areas of high support, stretch and breathability where you need them most-without overlays, which add weight. For an adaptive fit, lightweight dynamic Flywire wraps the foot and is adjustable through the laces.LightweightNike Flyknit technology renders this racing shoe incredibly lightweight. The upper and tongue weigh just 34 grams (1.2 ounces), and the entire shoe weighs a mere 160 grams (5.6 ounces).Nike 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, form-fitting and virtually seamless upper.