Type 98 Model 1 (Mk2) is 144Mil with 9 divisions of 16Mil. Performed some wing Mil calcs at 200, 300, 600yds against P40, F6f, B25, B17 and B29. It was the only way to make the 9 divisions be useable at ww2 combat ranges. Pretty much makes it a 4RAD reticle.
That's why in the youtube films it doesn't fit on the reflector plate. The large size was to account for bombers later in the war. The red orange filter you see flipped on from the white reticle is a night filter as there is an amber sun screen that can be lifted up while the day white reticle is used to keep the white reticle from disappearing in bright light. Another use would be with white clouds around. That became a problem for the K14 white reticle fixed and movable against the tropical cloud formations in the pacific.