Above are the outer clamping plates, these are really just dressing, however, without them it leaves the steel structure of the tibia and some very sharp edges exposed. With these in place it finishes the end of the tibia nicely.
This is the main part of the 3 axis design. This part gets clamped between the two steel plates of the tibia. The M20 x 160 bolt holds the rest of the foot in place.