We can’t all be experts on every little thing. There are some things out there we’ll need a bit of extra help figuring out. Luckily, when you have a whole community to talk to, you can get answers pretty quickly.
The Reddit users who frequent the r/whatisthisthing sub were pretty helpful in identifying these items, which left some people thrown for a loop.
“These strange dust patterns keep showing up on screens of my apartment windows.”

If you smoke, you may know what’s going on here. But for the rest of us, Reddit user Snowball-in-heck has our backs: “Previous tenant smoked w a fan in the window.” Huh, it really is that simple.
“Flew over my house tonight. Seemed like maybe a low flying satellite but it had this tail and the brightness wasn’t constant.”

Usually I look at these things and my mind goes to UFO. But it’s never a UFO.
Apparently, this time I was kind of close, though. According to Redditor bright_shiny_objects, it’s the Falcon 9 launch. As in, a rocket. Space wins again!
“While breaking up tile in the bathroom, there’s this additional layer between the tile and the previous laminate flooring. All these small and hard white beads crumbled out of it.”

Renovating rooms can come with a serious risk. You never know when you’re about to run into some asbestos, mold, or even mouse droppings.
Luckily, though, this is just foam beads from cement boards. It is a bathroom, after all.
“Small electronic device with camera found plugged into outlet outside of a chain restaurant. Device has 3 components and an outlet plug for a power source.”

The explanation for this one is kind of weird, if you ask me. It’s some sort of plug-in mini spy camera. I guess there are plenty of non-creepy reasons to have one, though.
“It’s metal, I think it came from the oven a few rentals ago and it has followed me ever since. Seems welded together and has no give in it. I thought it was maybe some sort of handle or related to the shelves.”

This person’s had this mystery item for quite some time. And yet, KateAndSidneyPie on Reddit was able to quickly identify it as a grill pan holder. Nice and easy.
“Green rectangular key with 3 pins on one end and CISCO, CAS, and a ‘0’ printed on it.”

It took several Redditors to explain what this thing is, but from what I’ve read, it’s basically some kind of resistor used for television and internet cables. And from the comments, this particular model is kind of old. So, that’s it.
“Metal frame with swing-like thing which looks like a curved snowboard.”

To me, it looks like some kind of gymnastics bar. But what is that weird, curved snowboard-looking thing in the middle?
Well, cat-catastrophe, the OP of the post, figured it out. It’s a really strange firewood holder. Another mystery solved, sort of.
“These little boxes are in the top corner of several rooms in my house. Approx 7x2x2cm.”

Could it be related to power of some sort? Like, is it an electronic plug or something?
Well, according to Redditor toodog, “That’s a burglar alarm junction box, I expect inside you will find a 6 or 8 core cable to wire a passive infrared movement detector or PIR.” Neat.
“Oblong aluminum and hard rubber. Barrel tip is textured brass with magnetic tip. Pointed end has two raised bumps, maybe used to attach to something.”

Apparently, this thing was found among some craft supplies. But that doesn’t answer what it is.
Thankfully, samt183 knows what’s up. “It’s a handle. Usually the knurled bit unscrews so you can add like a hook on it. Good for picking vinyl cut outs.”
“Clear plastic dome/bell on top of this homemade enclosure the base is around 21″ diameter at base, about 17″ middle diameter, about 22″ tall, about .33″ thick at base.”

According to loonlakeloon on Reddit, it’s called an Ecodome. I tried looking it up on Google and couldn’t really find anything, so I guess it’ll still remain a bit of a mystery.
“Black metal frame, flaired, measures roughly 44″x 33″ at base, attaches at corners with tabs, has 2 screws per side on the top edge, gray/black powder coat.”

It almost looks like a picture frame, except for the fact that it’s made of welded metal. Maybe it has to do with fencing or stair railings?
Well, no. It looks like it’s some kind of tray to catch birdseed and stuff from a bird feeder.
“So I have this metal mechanism and I have no idea what it is.”

Reddit user sandiercy said it was “the feeder mechanism for a dot matrix printer.” And you know what, that’s probably the best answer we’re going to get, so I don’t think it would be a bad idea to just roll with it.
“Royal mail cabinet with no slots by the side of the road in North of England. What is this cabinet for?”

This one is actually super interesting. Reddit user agamemnonIV said, “It’s a pouch box. Posties have their sacks delivered to them via these storage boxes.”
You really do learn something new every day (and in a list like this one, you’ll learn a lot of somethings).
“This was in my bandaid wrapper instead of a Band-Aid. Almost rubbery. Solid construction, not sticky, same on opposite side.”

Something tells me you can’t use it as a bandage.
But what is it? I’ll let Redditor amykake explain:
“This is a Mylar overlay used for quality control. You place it over a cut adhesive and use a Calliper to measure the max differential in length and width.”
“Reel of 600 small rectangle objects.”

A surprising amount of people knew exactly what this roll was, and chimed in on Reddit. It’s a bunch of heat sinks for circuit boards, which apparently come in large rolls like this. That’s actually a really cool find if you ask me.
“Metal wired loops with colourful beads in between, the entire thing can turn inside out to change its form.”

Well, whatever it is, it’s really pretty.
“It was a prize from one of those fundraisers at school for selling cookie dough or gift wrap or something. It’s just a novelty toy,” says ThisFeelsLikeATest on Reddit. So, it’s basically nothing special. Still pretty.
“3-inch long blue plastic cylindrical object magnetized on both ends with two screws in the middle?”

This one was a bit of a group effort. It’s part of a toy called Magnetos , which is some kind of magnet-based thing that kids can build different structures with.
Thanks to Reddit, we got to learn about a pretty neat toy.
“Green pellets found in shed. No label on bag. Friable, no discernible odor.”

There are plenty of kinds of pellets that are used for so many different things. Some are for rat/hamster cages, others are for kitty litter, and some could even be used for barbecues.
These ones, though, are rat poison. So uh, steer clear.
“Little red dot, metal border. No idea other than that?”

A few different people had a few different ideas of what this strange little disc could be. But as it turns out, it’s nothing more than a super old bingo chip. Must’ve been used for a lot of games back in the day.
“What is this bucket with gears?”

I’m going to go out on a limb here and guess that this whole mechanism is used to mix something.
And that something, as Reddit commenters have pointed out, is dough. Makes sense, since there’s what looks like a dough hook in there and all.