Thats beautifull binoviewer made in Japan, by Takahashi, made in April of year 1996, and there was made only 1 run of these, in very low quantities.
Mechanics, as expected, made by high Tak percision.
Bino is angled at 45 degrees. (same like Angled Carl Zeiss binoviewer)
Eyepeice holders works very smooth, as real self centring design.
By changing IPD, you actually change focus, which can be annoying for some, but for most, and me, its not problem at all. (same like Angled Carl Zeiss binoviewer)
On back side, there is 2x Takahashi OCS which can be very easily removed - unscrewed.
Telescope connection is 2" unscrewable.
Techniall specifications unknown untill today:
Prisms diameter: 22mm
Clear Aperture (lowest, effective): 13mm
Optical path (without 2x OCS installed): 14.3cm
Optical performance excellent, like expected from Takahashi company.
I did short comparation Takahashi binoviewer vs Carl Zeiss Angled binoviewer:
Generaly, pict quality same as Zeiss, except Tak bino have several more ghostings vs Zeiss on bright objects, especially Jupiter (not bothersome for me, just ignored them).
Zeiss is more robust and feels more compact.
Tak is lower in weight, and takes more light path vs Zeiss.
Zeiss have much more effective Clear Aperture.
Tak is much more complicated to collimate vs Zeiss.
While field top 13mm is setted deeply inside binoviewer (on back side of beamsplitter), it allow to using eyepeices with much larger field stops than 13mm to not notice vignetting directly.
Denis, binoviewers expert