The Nike Free Focus Flyknit 2 Women's Training Shoe features an innovative sole that expands and contracts with every step—plus Flyknit construction for snug comfort and lightweight breathability. Benefits Lightweight Flyknit fabric is flexible and breathable Flywire cables provide a snug, locked-in fit Foam sole for ultralight comfort Tri-star outsole pattern expands and contracts with every step for natural mobility Rubber sections on the sole for durable traction Flyknit Origins 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.