Nike's most natural ride to date, the Nike Free RN Motion Flyknit Men's Running Shoe features a supportive, conforming Flyknit upper and a revolutionary new midsole pattern that allows the shoe to expand, flex and contract with your foot during every step—so you can move more freely than ever before. Superior Natural Movement The next-generation Nike Free midsole expands in multiple directions thanks to an entirely new tri-star pattern, adding a new dimension of flexibility that delivers maximum dynamic movement with every stride. Plus, the heel is rounded to mimic the shape of your foot and roll naturally with the ground. Enhanced Cushioning The dual-density midsole uses a softer foam core directly underfoot and a slightly firmer foam carrier to deliver cushioned comfort and durability for a smooth, natural ride. Snug Fit Strong, single-seam Flyknit includes stretchy polyester yarn for a compressive fit that moves flawlessly with your foot as you run. Flywire cables woven into the upper can be tightened through the laces for dynamic support. More Details Notched collar for easy on and off Rounded heel for natural range of motion Lightweight solid rubber segments under the toe and heel for enhanced traction and durability Weight: 213 grams approx. (men's size 9) Offset: 4mm 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. 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.