Leatt Z-Frame Knee BraceLEATT Z FRAME MX MOTOCROSS & ENDURO KNEE BRACE We learned a lot from developing our C Frame and X Frame knee braces, and we heard your request for a good knee brace that won't break the bank. Thanks for pushing us! Not as stiff as the C Frame or X Frame, but a darn good chassis in glass filled nylon for comfort and a Carbon Injected knee for that rigidity whichreduces the ACL, Meniscus, and MCL injury risk. The Z Frame is also CE certified as a