Featuring the latest evolution of the exclusive Sidi vertebra system The vertigo 2 has a host of other features that will continue to make it the sales leader of the sport boot segment. Vertebra system adjusted via sidi’s Exclusive techno VR closure system helps to protect the rider’s Achilles tendon. A single nylon ankle support brace for Extra support. Double stitched in all high stress areas. Bolt on Replaceable, adjustable and aerodynamic nylon scuff pads on the toe. Closable air vent. All bolt on parts are replaceable. Dual compound sole.