Interesting/obscure/cool as in “not your every day item”, or stuff with an interesting history.
I’ll start with my pair of pilot earphones from the 1970’s used in DC10s, these are pretty cool because of the suction they have, you put them on and they suck all the air out of your ears, I’m pretty sure this is to counter pilot’s ears from being hampered by pressure changes, so they don’t risk missing out on any ATC messages.
They work on PCs with an adapter but the sound quality is dreadful.
I also have a Russian GP-7 gas mask from the 70’s, likely the same model used during the Chernobyl cleanup. A lot of people fear these things have asbestos in the filters but as far as I know it’s a myth and was only used in really, really old gas masks from <1950s.
I also have this 3.5GB IDE hard drive from 1998, I have no idea if it works or what’s on it, but I’m going to say it’s probably got Windows 98 on it.
Here’s a comparison between a 500GB laptop hard drive from 2014 and this ancient beast.
So yeah, show of your cool stuff!