MBT Fanaka GTX Chocolate at Robert Frost Fine Footwear and Frostshoes.com. MBT Fanaka features full grain nubuck leather with a buffed surface. The Gore-Tex membrane is completely waterproof, but permeable for water vapor. This allows moisture to escape from the shoe but water cannot penetrate in. TPU and glass fiber shank adds firmness to the sole construction and also a natural rolling movement of the foot for even weight distributribution. PU midsole with pivot is the balancing section underneath the metatarus which requires an active rolling movement with every step. This activates a large number of muscles throughout the body when walking or standing. Masai Sensor (Masai Barefoot Technology) creates a pleasant feeling when walking and/or standing. MBT Fanaka GTX Chocolate men's Gore-Tex comfort technology shoe available at Robert Frost Fine Footwear and frostshoes.com has fit true to size.