SIDI Rex BootsTaking their place at the forefront of rider technology, the SIDI Rex Boots feature cutting-edge closure mechanisms, an ergonomic entry system, unmatched adjustability and progressive protection to make them one of the most comfortable and secure sport boots on the market.Constructed using SIDI's exclusive Technomicro Technomicro is a composite microfiber material created from strands, each one less than one thousand the thickness of silk. These fibers act like natural leather but with the advantage of more strength, softer texture and lighter weight. Technomicro is also highly abrasion resistant. base material with strategically placed padded elastic panels that widen as your foot passes through, the Rex Boots offer an easy, uncomplicated fit. In lieu of tedious laces or limiting ratcheted buckles, the Rex Boots utilize SIDI's proprietaryTecno-3 Push Closure System. Three separate and adjustable steel cable closures are released and secured by circular dials with push buttons that allow the dial's arm to be lifted and rotated for increased closing pressure. The mechanisms located at the shin and ankle pull from the center while the instep mechanism pulls from the boot's inner edge to create a symmetrical closure and ensure a firm, confident fit.The Rex's single ankle support brace, comprised of fiberglass infused nylon, restricts lateral movements and reinforces the internal and external ankle joint to offer increased support and stability. Additionally, air vents positioned at the bottom of the brace are operated by an accessible, aerodynamic button to provide optional airflow. Using a similar slider mechanism, an extra air vent is incorporated into the toe slider that offers increased optional airflow over your little piggies. In addition to the venting scheme, small slots located at the central point of the ankle support brace allow heat and perspiration to escape from within the Rex Boots keeping you cool, dry and focused lap after lap.Note: Customers have found these boots to run a little narrow/small and recommend sizing up if you are in between sizes.Features: Technomicro base material SIDI's exclusive Tecno-3 Push Closure System Elastic panels inthe front and rear of the boot in flex areas for maximum comfort A single ankle support brace, nylon material infused with fiberglass fibers,joins the internal and external ankle joint for more support The exterior ankle support brace is equipped with air vents Small ventilation slotsat the center of the support brace Nylon inner sole with removable arch support pad Double stitched in all high stress areas Fully encapsulated heel cup Lined with anti-abrasion Cambrelle in the foot area for comfort Perforated Teflon treated nylon lining Toe slider comprised of nylonreinforced with fiberglass and fitted with anair intake and an innovative alloy insert Dual compound sole DuPont® polymer toe shift pad CE certified to EN13634:2017