Shock Absorbing Heel Cup Three stage, shock absorbing heel cup molded in three different densities of plastic is one element that sets the Vertigo series apart from all other sport boots. This system offers a built in shock absorbing range of 3mm. The heel cups internal area is also fully lined with impact resistant thousand-air cell memory foam for and extra level of comfort and protection. Lining Each Vertigo series boot is lined throughout with lightweight perforated Teflon treated fabric in order to allow moisture to breath out to the Lorica outer and dry quickly with no mold build up in the long term. Additionally the inner ankle area of all Vertigo series boots are flly lined with Sidis own formula of perforated closed thousand-air cell memory foam. Tecno VR System The Vertigo series of boots are the only race boots to offer a patented Tecno VR adjustable calf system designed to accommodate calves of virtually any size in a clean, supportive and protective design. With a simple adjustment of the Tecno knob the internal onofilament line will evenly close and wrap the boot around the riders calf in micro adjustments for a perfect fit. A maximum adjustment of 5cm is provided. Replaceable Shin Deflector and Scuff Pad The Vertigo Series offers interchangeability with its front shin guard and toe scuff pads. Choose from carbon or nylon shin piece, and either a ceramic or nylon toe scuff. Air Vent System Both the Vertigo Corsa and Vertigo employ an air ventilation system that can be opened or closed with a touch of a button depending upon a riders needs. This Malleolus guard on the outer edge of each boot also protects the small and vulnerable foot bones. Composite Inner Sole The composite inner sole of Sidi boots resists side to side compression offering greater protection compared to the leather inner soles that our competitors use. The insole features a removable arch support and will never lose its dynamic characteristics, even after months of intense use it is water resistant and is designed to withstand high footpeg pressures. Replaceable Parts Every bolt on component of each Vertigo boot is available separately. Riders can change the various components to replace items that have worn or have been damaged in a crash. Lorica Boots outer is fully constructed with Lorica, a composite micro fiber material created from strands less than one thousandth the thickness of silk. When injected with special resins, these fibers act like natural leather skin, but with the addition of better strength, softer texture, lighter weight and better moisture protection. Features The patented and trademarked Vertebra System protects the riders Achilles tendon Replaceable thermoplastic resin ankle ball protection cup Bolt on (no Velcro!) replaceable, adjustable and aerodynamic nylon scuff pads on the toe Removable arch support Double stitched in all high stress areas New elastic panels adjacent to the entry zipper allow a bind free zip and improved fit Dual compound sole DuPont polymer toe shift pad Top grain leather construction Equipped with a GORE-TEX waterproof-breathable membrane Mega version offers an EE width as well as increased room all around the arch area