A pretty little cassette recorder kit. Comes in a nice case, with speakers, a dynamic, stereo mic. (F-99S), and stand. Apparently the first tape deck that recorded in stereo.

The Microphone has a bit of an odd plug though: two 3.5mm jacks, plus a smaller one in between that says it's for 'remote'. They're tip+sleeve, so unbalanced. This video has it wired up normally, and there's a comment with advice: 'Simple solution: 1- ignore the middle pin, 2- use P2 to P10 adapter for each channel, 3 → mixer, 4. Pan L and R for each channel and done!! Amazing Vintage Stereo sound!'.
So I guess you just ignore the middle pin. I thought I tried that, but I'll have to give it another shot.
Found one on Reverb with an XLR jack.

There's also a car adapter available for it, the TB-2.

The picture used on this page is a bit distorted, stretched vertically.

I need to replace the belt (I think). It's not easy to access. Top part doesn't come off by itself, and after getting the bottom part off there's a lot of stuff to dig through.

Can't find a service manual. User manual doesn't have any advice, closest it has to anything technical is a circuit diagram.

Internals mights be similar to the TC-110, but haven't found any service manuals for that either.