The Charee Callies Flats by Hush Puppies are combination of nubuck and full grain leather uppers. Molded rubber outsole provides excellent traction and durability. HPO2 flex technology, provides the ultimate in cushioned comfort - padded insoles with a unique triangle design, offers a multi-directional flex capability, conforming to the way you walk. Zero G technology provides lightweight comfort and exceptional flexibility. Material: Leather, synthetic.