Medically Certified Mono-Hinge Protection. Super stiff, mono-hinge frame with three-point force distribution. Hybrid AirFlex impact gel knee cup with hard shell slider for ultimate knee brace comfort. Reduction of forces to limit knee injuries: ACL, meniscus and MCL. Very low-profile inner knee for superior bike feel. Certified as medical device: EU CA014741. USA FDA 10048761. CE tested and certified as impact protection: Knee EN1621-1. Hyper extension limitations 10°, 15°, 20° and 25° for ACL injury reduction. Engineered, lab tested built-in fracture points. The C-Frame chassis is designed to break before injuring: The shin bone (Tibia) or the thigh bone (Femur). Comfortable, low-profile shin bone plate with load distribution pad that fits inside all boots.