Vionic with Orthaheel Technology Women's Nell Boot Synthetic Imported Rubber sole Comes with removable Orthaheel Orthotic Technology. High quality- man made uppers with unique styling and comfort adjustability. Premium 'Active' removable biomechanical orthotic footbed that supports your feet and helps realign the lower legs for all day comfort. Rubber outsoles with unique wave-patterened tread for improved traction. EcoFresh anti-microbial- odor-reducing footbed and linings.