Alpinestars unique, specifically developed, replaceable, three-piece Supermoto outer sole. Fixed, one-piece, main area for rigidity and structural strength. Replaceable heel and front outer foot sections for sliding and wear resistance fit absolutely flush with the fixed sole to create a smooth, uninterrupted surface. The replaceable heel and toe sections are formed with a specially developed rubber compound and are affixed to the boot with mechanical grip tabs and steel screws with a washer and raised screw head protection to ensure the screws and assembly are not damaged by wear and impacts. Full-grain leather with impact and abrasion resistant PU shell for unmatched levels of safety. Closure system features 4 aluminum buckles with memory settings and a quick release/locking system with self-aligning design for easy, precise closure.