The innovative Nike Flyknit Racer Unisex Running Shoe 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.The one-piece knit upper seamlessly integrates areas of high support, breathability and stretch 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.A Nike Zoom unit in the forefoot offers low-profile, ultra-responsive cushioning. The full-length, compression molded Phylon midsole provides even more lightweight impact protection.The waffleskin rubber outsole features a racing-specific diamond pattern, delivering lightweight durability and traction. Outsole lugs are raised slightly under the forefoot for enhanced grip and comfort at toe-off.Nike 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.Flywire helps provide ultra-lightweight support and comfort for your foot. It gets its strength from thin nylon fibers strategically placed on the upper of the shoe to hold the foot in place, helping to reduce slippage during activity. This allows for a massive reduction in weight because material is used only where it’s needed for structure.Features Include:Reflective elements for visibility in low light.Pull-tab on heel for easy on and off.Low-profile knit tongue for ventilation and comfort.Weight: 158 grams (men's size 9).