My friend saw this smoke detector for sale with a bunch of other devices. We’ve think it’s some kind of BRK. (it’s also on top of a BRK box)
Your friend should definitely buy it (& I guess all the other stuff being sold with it as well) as it definitely looks rare: I’ve certainly never seen a detector like it!
Unfortunately it’s a large lot with quite a few other detectors and alarms so it was like around $200 for it all and we would have to drive to get it.
This BRK ad from 1982 shows a similar detector, which is identified as a 2751. The detector shown in the ad isn’t identical, however, as the head features a black disk; I’m unsure of the purpose of this disk.
This must be quite a bulky detector. The photo in the ad makes it look comically large.
This definitely helps and shows there are more similar models, I can’t imagine the model of the one my friend found is too far off.
It’s almost definitely a heat sensor, it’s usually silver but either the camera or printer messed with the colors.