The Nike Free 4.0 Flyknit Running are a flexible and cushioned running shoe that promotes a more natural stride with a lightweight supportive Flyknit upper and incredibly flexible minimal outsole. With a Flyknit one-piece upper made completely from polyester yarn the Free 4.0 Flyknit combines areas of stretch and structure for super lightweight support and glove like fit. Knitted Flywire cables hug the midfoot for additional support where it's most needed. Hexagonal flex grooves are hot-knife cut into the outsole and wrap around the sidewall to help your foot move more naturally in all directions. Secondary cuts are designed to intersect the flex grooves to grant even more flexibility. The heel shape is designed to mimic the shape of the foot so your foot rolls with the ground for a natural footstrike. A minimal 6mm offset between heel and forefoot height means your feet are closer to the ground to provide a more natural feel along with a combination of cushioning and support. - A.D. Attached Nike Flyknit tongue with notches for easy entry Minimal sockliner moulds to your foot's curvature for added support and comfort Non-stretch knit-in heel for structure and support Asymmetrical lacing for reduced lace pressure on the top of your foot Waffle outsole lugs help absorb impact and add responsiveness Weight: 238 grams (men's size 9)