The Crispi Altitude GTX was conceived and built with a desire for breathability and technical fit, combined with the foundation and long-lasting comfort of the EFX dual-density polyurethane midsole that hunters rely upon when long miles and the occasional heavy load is expected. With a constant and even flexing board last construction (Flex 2.5 rating) and exclusive VibramA(R) Megagrip outsole, traversing variable terrain is a breeze. Crispi has added features like ultra-soft leather and synthetic upper, the Crispi Thermo Wire Technology, and a full PU-coated leather rand to ensure the Altitude GTX will endure well whatever hunt or adventure you embark upon. The Altitude GTX is a new kind of hunting boot ready to provide all-day comfort, optimal performance, and ground feel that traditional boots haven&&';;t been able to deliver. Gore-TexA(R) waterproof lining 2.5 Flex Rating Not insulated EFX dual-density polyurethane midsole VibramA(R) Megagrip outsole Board Lasting Mechanical Construction - perfect connection between torsion rigidity and flexbility Crispi Crossbow Frame - offers perfect stability, absorbs shock, and improves braking in difficult terrain