Unlike with a Real Grade kit, I had to build the inner frame of the legs piece by piece. I wondered how exactly that would work in regards to articulation. The pre built frame pieces of a Real Grade kit are fairly complicated, full of pistons and joints that slide in and out to give them their range and flexibility.
With this Master Grade kit, that same flexibility is brought about via the use of the same kind of “inner rail” system that I encountered in the shoulder armor. You start with two pieces, each with a railing along the inside. Another piece, with pegs on each side, is placed between them, such that the pegs slot into the rails. This allows the inner piece to not only slide up and down, but also rotate. And when that inner piece is essentially the unit’s knee, it becomes clear how it achieves the excellent articulation associated with this grade.
The inner frame showing a bit of bend