The new One 2.5 is built for speed, without sacrificing the comfort needed to maintain that speed through the finish line. A FootShape™ toe box lets your toes relax and move freely for incredible comfort, extra stability, and a more powerful toe-off. Innerflex™ technology adapts to the flexion of your foot with omnidirectional flex grooves in the midsole. Responsive A-Bound™ cushioning protects the feet at impact and rebounds to add a spring to each step. The weight-balanced, Zero Drop™ platform helps you maintain low-impact form, even when fatigue sets in at the end of a hard race or workout.