Medically Certified Cage-Type Knee Protection. The X-Frame Knee Brace is made of injected carbon composite and is the latest innovation in the Leatt knee brace range. Engineered to help reduce forces to the knee, it limits knee injuries and is CE Certified as both a medical device and as impact protection. Sporting asymmetrical hinges, the inner hinge is 40% slimmer, providing superior bike feel during riding, whereas the outer hinge's durable metal gears offer precise movement. The X-Frame provides a comfortable fit with an easy strapping system, interchangeable hinge padding sizes, and a low-profile shin bone pad that fits inside all boots. Injected carbon composite frame. Asymmetrical hinges. 40% slimmer inner hinge for superior bike feel. Metal-geared outer hinge for precise movement and durability. Reduction of forces to limit knee injuries: ACL, Meniscus and MCL.