The Beast®(men's) and Ariel (women's) have long served as motion-control superheroes, coming to the rescue of runners with low or flat arches and excessive pronation. Now, a new full-length MoGo midsole extends the shoes' list of superpowers, with super soft, long-lasting cushioning offering increased energy return for some extra spring in your step, all with no sacrifice in stability. Featuring silver-embedded X-STATIC®, The Silver Fiber™, in the sockliner for a comfortable, thermally balanced footbed, the Beast® and Ariel deliver maximum support and smooth, crave-worthy cushioning that feels as good on mile one as mile 100--and beyond.