Xero's CEO Steven Sashen designed this shoe in collaboration with a former Nike footwear developer. Sashen himself competes in masters-level sprint races and uses these Speed Force 2 shoes in many of his training sessions, as well as in races. The construction is extremely lightweight and minimal, even for a barefoot shoethis is the lightest model the brand offers. If you want to take minimalism to the extreme, you can even remove the insoles! Like the original version, this second edition performs well in a variety of workouts, relaxed evening runs, or even on the padel court. Compared to the first version, it features a more breathable upper material and uses welding technology to bond materials togetherin practice, the materials are fused. - The wide last allows your foot to spread naturally - The total thickness of the FeelTrue sole is 4.5 mmthe highly flexible sole enables proprioception, meaning your foot can sense exactly how your weight rests and moves on the surface -