Guiding every step to feel-good runs.For those who crave reliable comfort on the trail and need some support, the Guide 13 gives the best balance of feel-good cushioning, ultimate traction and fluid guidance through the gait cycle.Overview? New PWRRUN cushioning provides just-right softness that's responsive enough to tackle as many miles on the trail as you wish.? The new medial TPU guidance frame quickly and quietly guides each foot through its natural gait cycle for the smoothest feel yet.? FORMFIT surrounds the foot with a made-for-me feel that can accommodate a wide range of foot shapes comfortably.? Trail designed, extra sticky rubber outsole lends ultimate traction when you take run off road.