Not a TK6 : this is for serious people !
The TK320 is a TK340 reduced to 2-track - no bouncing.
Still a tube open-reel recorder with many features allowing sound fidddling with its two tracks and three speeds : recording each track separately and adding echo (or not) along the way.
Being a half-track, record can only happen in one direction. Play as well, unless you are able to listen backward.
Other than that, here lies the usual Grundig mix of multi-lingual scripting with Umspulen next to Pause, cute-as-can-be counters placed inside the top of the rec and play level knobs, six tubes, fourteen semiconductors, and two built-in 12W amplifiers+loudspeakers.
I don't own a TK320 but I do have an early 1960s brown & white, tubed, and ravishing TK15/3D which I'll never part with.
Too pretty and 1960s-ish to be true.
The image here come from a beautiful july 1966 french catalog.