Designed to limit foot / ankle hyperextension. Italys finest top grain leather is used as a base material, as it stitches to the TA sole best, with laminated 3 mm Technomicro material being used on the tongue and rear joint areas for the best in flexibility and comfort. The TA sole is best suited for riders who may walk in their boots some. The TA sole is made of anti-skid rubber and can be replaced by a cobbler. The TA sole features excellent rear brake feel. Fully adjustable calf area. Nylon insole - no dangerous steel shank! The boots tongue features a protective internal gusset. Removable arch support. Inner heat shield made of high grip material. Toe area covered in protective plastic. Rigid, shock-resistant, anatomically shaped heel for maximum protection. Replaceable, even sleeker, micro-adjustable cam lock buckle system with memory retention straps. Lower buckle protected against opening from impact by a molded guard. Lined with anti-abrasion Cambrelle in the foot area for comfort, the upper is lined with Teflon mesh which prevents complete absorption of water and sweat. All bolt-on parts are replaceable; replaceable shin plate is a Sidi patented feature. Replaceable inner kickstart / footpeg guard on the inside area of both boots. Slim, cool non-bootie design. Malleolus external molded plastic guard with ergonomic closed cell foam padding internally to enhance protection of those tender small foot bones. Exclusive Dual Flex System upper offers the industrys best fit, especially with knee braces!