This is the newest CB2.5 bottom plate. This updated bottom plate has both the M2 and M3 FC holes offset just like the CB3 giving you the most room for max camera tilt no matter what stack you choose to build with. The latest bottom plate is a bit longer the previous versions. This was done to push the camera forward a bit to help remove the props in view. The new plate is also wider allowing the camera to move forward between the standoffs but not to far so the camera is still fully protected by the standoffs.