The Mephisto Nautic has a smooth leather upper with contrast stitching for classic style, while the Deer skin / thermoregulation foam-lined uppers and Deer skin foam / latex removable footbed provide the utmost in comfort. The Mephisto Nautic also features the patented Translucent Air Bag System¬®_ô: a rubber compartment built inside the heel with a valve structure. This airbag is specially conceived and prepared to conform to the irregularities of any terrain during walking. As the shoe enters into contact with the walking surface, this airbag compresses to absorb the shock and act as a protective buffer zone for the foot. In addition, the Nautic has a combo Phylon / Caoutchouc rubber outsole is flexible, lightweight and designed to protect your feet from the jarring effects of walking.