DYNAMICALLY FLEXIBLE. NATURAL FIT.More cushioned than the Nike Free RN Motion Flyknit, the Nike Free RN Flyknit Men's Running features a newly designed midsole pattern that expands, flexes and contracts with your foot with every step. Its sock-like upper provides the incredible fit of Flyknit for total comfort throughout your run.Move NaturallyThe next-generation Nike Free midsole expands in multiple directions thanks to an entirely new tri-star pattern, adding a new dimension of flexibility that lets your feet move more dynamically with every stride. Plus, the heel is rounded to mimic the shape of your foot and roll naturally with the ground.Soft CushioningSofter than previous iterations, the new midsole foam delivers exceptionally comfortable cushioning and lightweight durability for miles.Incredible FitThe single-seam Flyknit upper provides an incredible sock-like fit with targeted areas of high breathability, stretch and support. Flywire cables woven into the upper can be tightened through the laces for dynamic support that moves with you.More DetailsNon-stretch heel material for added structureRounded heel for natural range of motionLightweight solid rubber segments under the toe and heel for enhanced traction and durabilityWeight: 225 grams approx. (men's size 9)Offset: 8mmNike Free OriginsAfter learning that Stanford athletes had been training barefoot on the university's golf course, three of Nike's most innovative and creative employees set out to develop a shoe that felt natural and weightless, similar to bare feet. The team spent eight years studying the biomechanics of runners' feet in motion. The results yielded a profound understanding of the foot's natural landing angle, pressure and toe position, allowing Nike designers to build an unconventional and flexible running shoe from the inside out.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, formfitting and virtually seamless upper.