SIDI Fusion Air Boots Fully perforated for summer riding Vertebra system Achilles and rear calf protection panel. Replaceable nylon toe scuff pad. Replaceable outer ankle protective cap. Nylon shin deector plate. Fully encapsulated heel cup. DuPont polymer toe shift pad. An elastic panel adjacent to the entry zipper allows a bind free zip and improved t. Removable arch support. Double stitched in all high stress areas. Zipper and Velcro closure system. Lorica outer construction. Perforated Teon treated nylon lining.