Daily Training / Speed Days; Lightspeed - A stripped-down design keeps the shoe featherlight, freeing up energy for what matters most; Fast Forward - SpeedRoll technology turns strides into momentum, rolling you smoothly from step to step; Run Fast Any Day - XT-900 rubber delivers long-lasting grip, so you can push your pace with confidence; Support Category: Neutral; Offset: 8mm (40mm/32mm); Weight: 7.5oz (212g)