The Sidi ST Boot features an easy entry system as well as the finest support and protection features. The patented and trademarked Vertebra System protects the rider's achilles tendon. There is bolt on replaceable, adjustable and aerodynamic nylon scuff pads on the toe. The boot is double stitched in all high stress areas to ensure durability even after repeated use. A dual compound sole and DuPont polymer toe shift pad means the boot won't be falling apart because of the parts which come under the most stress and use. A perforated Teflon treated nylon lining means a very tough but breathable layer so that the boot stays strong without making the boot too hot.