The anatomically contoured PU shin plate is designed to enhance protection, with its structure extending beneath the upper for added safety.

The upper portion concludes with an elastic gaiter that includes an anti-heat protection panel. This gaiter is sealed using a soft PU Velcro strap, effectively preventing the entry of rocks and debris while offering a broad adjustment range.

The Crossair SL features a 3-buckle closure system, with each buckle operating independently. Each buckle consists of a notched strap and a hook with micrometric adjustment memory. All elements of the buckle system, including the buckle, strap, and hook, are replaceable. These buckles have a single fixed point secured by a screw, ensuring effortless closure and allowing the boot to adapt to the rider's leg for enhanced comfort.

The Crossair SL incorporates two flex points. The first hinge is located beneath the ankle, reducing bulk and creating a smoother, more aerodynamic interior for the boot. Inside the boot, a support brace restricts excessive movement to prevent hyperextension of the ankle, instep, and the Achilles tendon, enhancing rider safety.

The second joint, positioned above the ankle and working in conjunction with the lower hinge, enhances the boot's flexibility, allowing for a seamless bending motion without compromising on rigidity and lateral protection.

The boot incorporates three removable anti-hyperextension systems for the foot. The first is situated at the initial hinge, the second is positioned at the back of the boot (preventing excessive backward bending by supporting the ankle), and the third is located at the front. The third system utilizes an innovative mechanism with a replaceable insert, enabling a tailored range of tibia flexion and locking in place to prevent overextension. Additionally, a PU bootleg, connected to the ankle strap via the second hinge, serves to shield the back of the boot and is sandwiched between the upper and the lining.

The boot leg features a suede calf section cover enhanced with embossed rubber inserts. These not only offer excellent grip when in contact with the bike but also serve to shield the leg from heat. The rubber inserts are also present on the interior side of the ankle.

Crossair SL features redesigned plastics throughout. The boot's toe is entirely encased in protective plastic with an enhanced geometric pattern for superior grip. Metatarsal protection is integrated with a rigid, replaceable nylon insert, safeguarding the boot's interior should the rider's foot slip off the footpeg. The PU heel is specially shaped and molded to enhance foot safety in case of torsional twists, all while ensuring comfort and stability.

To enhance the lower buckle, a spoiler has been added to deflect debris away from the buckle. The ankle panel, along with the central strap, can be easily replaced with four screws connecting it to the boot. This panel comes in two sizes, catering to both 40-45 and 46-47 ranges.