The Sidi Colin Edwards Replica Air Boots have been constructed with Lorica and lined with Teflon vented mesh. Lorica is a composite micro fiber material created from fine strands ( 1/1000 the thickness of silk); when injected with special resins, these fibers act like natural leather skin but with better strength, softer texture, lighter weight, and moisture protection. The rear upper part of the boot is made up of two mechanisms. The first is the Tecno Calf Tensioner, this adjusts the leg circumference. The second is the Tecno Shin Tensioner, this helps the calf tensioner close the leg upper on the front part of the boot. This system is reinforced with fiberglass. It supports the ankle and is easy to replace. This system also allows excellent flex movement front to back while being firm side to side. These Sidi Boots have an incorporated air ventilation system. This consists of a third brace that is positioned on the outer lower part of the boot and features an air intake that can be operated by an aerodynamic shaped button. Another useful feature is the Tecno Instep Positioner. This is a fastening system on the front part of the foot on the instep. Some other features include: a shock absorbing heel cup for impact protection, a shin plate, gear change pad, and a vortice slider. The vortices slider is a toe slider made of nylon and reinforced with fiberglass. The Sidi Vortice Air Boots also have a brand new feature, the racing SRS sole. This sole has been constructed from a polyurethane and rubber blend, and are replaceable. Check out the Sidi SE Colin Edwards Vortice Air Boots, Sidi gear, and other riding boot options on our website: CompetitionAccessories.com!