The TU-D99X is a slim digital tuner which is the matching tuner for the AU-G90X and C-2101/B-2101. More info at http://www.fmtunerinfo.com/sansui.html#sansui-tud99x
I purchased the unit from the UK years ago. The unit has the matching wooden side panels which are not shown in the pix(s).
|After maintainence exercise|
Uploaded the following brochure of the D99X as the information is scarce on the internet.