The 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. 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.