ULTIMATE NATURAL FLEXIBILITY Our most flexible and natural ride, the Nike Free 3.0 Flyknit Men's Running Shoe features a lightweight, supportive Flyknit upper and an ultra-flexible, low-profile outsole that allow you to move more freely—and run the way nature intended. Ultralight Support The Flyknit bootie upper—a one-piece layer made entirely of polyester yarn—seamlessly integrates areas of stretch and structure, providing ultralight support and a contoured fit. Knit-in Flywire cables cradle the midfoot for added support where you need it most. Ultimate Flexibility New hexagonal flex grooves are hot-knife cut into the outsole, wrapping around the sidewall and integrating with the upper to enable more natural motion. Secondary hexagonal and horizontal cuts intersect the flex grooves for even greater flexibility. Natural Stride The heel mimics the shape of the foot, rolling with the ground to promote a more natural footstrike. 4mm Offset With a 4mm difference between heel and forefoot height, the Nike Free 3.0 Flyknit has the lowest offset of Nike Free running shoes for our most minimal ride while still offering great cushioning underfoot. More Benefits Compressive collar design hugs the ankle for a supportive fit Minimal sockliner molds to your foot's curvature for added support and comfort Waffle outsole lugs help absorb impact and add responsiveness Weight: 7.2 ounces (men's size 10) Nike Free Origins After 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. In 2002, they examined a group of men and women with pressure measuring insoles taped to their feet, using high-speed cameras to capture images of each foot in motion. The team spent eight years studying the biomechanics of shoeless running. 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. Since Nike Free's introduction, millions of runners have trained in the shoe, including some of Kenya's world-class runners. Flyknit Origins Nike Flyknit technology was inspired by feedback from runners seeking 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.