Walk on the wild side? How about a 10-mile speed hike? This Siren model features full grain pigskin leather uppers - what you need when the terrain is likely to give your shoes a beating. And for all its ruggedness Siren Nitro styling retains its feminine mystique. Vibram® Siren® sole for great stability and traction. Q-Form® triple-density molded footframe promotes healthy alignment for a woman’s stride.