This is the Sidi Vortice Air vented boot. The all-new Vortice is constructed of leather-like (but way stronger & lighter) Lorica, lined with Teflon vented mesh, with soft Cambrelle in the toe area. In the upper rear is the Techno Calf Tensioner to custom fit your calves, and up front, the Techno Shin Tensioner that helps close the leg upper on the front part of the boot. There's also the Techno Instep Tensioner, another GP-proven safety feature. The Vortice Air also features an air ventilation system, with adjustments on the toe area and outer-lower section. The shock absorbing heel cup insert will moves under impact and the front slider is made of nylon-reinforced fiberglass with a air intake and alloy insert. Underneath you'll find a poly/rubber blended sole with a replaceable center sole insert. The Vortice Air features replaceable parts like other high-quality Sidi boots. This boot comes in all black with red and white details or all white with black and red details. US sizing listed.