What the heck is this thing on the floor?

See attached picture. I've been using it as a drink holder occasionally, but I don't really need to, considering I can put spares in the side door pocket and my "main drink" in the actual center drink holder, well within reach. I mean, the thing looks like it was made to accommodate a single bottle standing up and something bigger (like one of those big tea bottles or a gatorade bottle) laying down.


Anyone have the definitive ID on this weird hunk of plastic I keep stubbing my toe on when I get up in the morning?

P.S. Don't mind the dirt and dust. I go to a lot of muddy places!

 

I thought so, too, but my extinguisher is secured elsewhere and there's nowhere for a strap or something to hold it down. Also, it's on the left side of the driver's seat where a shifter would be if this thing weren't an auto. Kind of a weird place for an extinguisher, but this is my first Freightliner, so I don't know if that's where it normally goes.

 

Military left, obviously

 

Yeah, I keep tripping on it and stuff. It's too far down to reach for a drink!