This is an Agile Septor 9-string guitar, which is specifically designed for people who want your normally tuned strings, but also want to go abnormally, ridiculously low.
I have it set up currently to drop A0, so the lowest string is a whole step lower than a 5-string bass's lowest note.
From low to high, it's tuned to A, E, A, D, G, C, F, A, D (so that's like D standard tuning with three extra low strings tacked on the bottom).
You can tune it to pretty much whatever you want, and there are all kinds of interesting tunings you can try.
This is basically only (as far as I can tell) for that person who wants to play the lowest, stupidest ultra-detuned post-djent apocalyptic satancore or whatever the kids are calling it, but who also wants to do noodly solo stuff up high too without losing that higher register.
This is a good price for one of these--not a lot of them used, and when they pop up they're usually in the $500 or $600 range.
Scale length looks like 28.
5" by my measurement.
A bit of cosmetic wear and tear, which I tried to photograph, but it still works perfectly.
The previous owner filed out the lowest string's saddle somewhat.
It's not visible unless you're looking really close or have the string off, in which you can see some of the black coating on the metal is worn off and you can see the bare metal underneath.
No functional difference as far as I can tell, other that you can now fit that preposterously large .
130 bass string in there.