The King of racing boot used to be the Sidi Vortice. But to every era comes an end. Enter: the Sidi Rex. These new hardcore racing boots will give you everything you need if you're the type of rider who likes to beat the stopwatch, whether it's on the track or on your daily route to the office. The Rex was developed through research, laboratory tests and "on the track" testing thanks to Sidi's MotoGP riders' input. The Vortice has always been an exceptional boot, but the Rex takes it to the next level.The Rex sports the new and improved closure system. The Tecno-3 Push rotors allow for easy adjustability with less hassle compared to the Vortice. The steel cables are now firmly attached to the boots and no longer rely on magnets to secure a good fit. The push button allows the rotating buckle to be lifted for an easy grip.. The whole system makes sure the shin and ankle mechanisms are closed symmetrically for a perfect, snug fit. The large ankle support brace joins the internal and external ankle joint for more support. In the outer lower part, you will find an effective air vent. On the calfs there's a large exhaust vent and on the toes you will find another intake vent. Sweaty feet are a thing of the past.The Sidi Rex comes in multiple colors and in both non-vented and vented (AIR) versions.