Neuromancer - Where can I buy a pack of Yeheyuans? and other conundrums

[[deleted user]]

Would anyone care to help me sort out which products are fictional and what they do? To start with, Yeheyuans are cigarettes of imaginary provenance, right? Hilton, Hitachi, and Kirin are real brands, but is Kandinsky? Octagon is a drug (an imaginary pill, I think), but what does it do? How does a cobra work?
Feel free to post your own questions or answers.

Edit: According to http://en.wikipedia.org/wiki/Neuromancer , Octagon is a Brazilian amphetamine, but I'm still not sure if it's fictional.

[Cairnraiser]

I've always imagined Octagon not as a brand, but as slang, based on the shape of the pill.

The Cobra is basically an extensible baton - I think it started out as a brand name, but is now a catch-all term for this type of baton. I think there are two versions of this; one that unfolds with the press of a button (think of a switchblade club) and one that extends either by pulling the top-end or can be extended by flicking the wrist (IIRC that's the one described in "Neuromancer")