Leaker shares final Apple 'AirTags' design in leaked pairing animation video
The unreleased Apple "AirTags" have appeared in a short animation that a leaker claims is the pairing video that plays when setting up your new tracker.

'AirTags' image concept from Front Page Tech
Known leaker Jon Prosser has shared another video with some new details about Apple's missing Tile competitor. "AirTags" have been rumored since Apple introduced ultra wide band (UWB) to the iPhone 11 lineup.
The short clip shows the "AirTags" spinning in an animation similar to what is shown when pairing AirPods to your iPhone. This gives us our first 360 degree view of the device from an alleged official source. Prosser has provided concept images before based on leaked video, but this is the first time seeing the design in its final form.

The first look at alleged official 'AirTags' design. Image Credit: Front Page Tech
The design is simple with a white-rounded back and a silver front with an Apple logo. It looks similar to a watch battery with a slight hump on the back.
The "AirTags" will use other Apple devices in a private network to track down your lost device. Similar to how Tile works, user privacy and data will be protected.
Apple's U1 processor equipped with UWB is expected to be utilized in "AirTags" for location within a few inches of precision. AR location finding features have also been discovered in previous iOS versions.

Apple 'AirTags' tracking tool final design shown in animation. Image Credit: Front Page Tech
Prosser asserts that the "AirTags" have been ready to ship for a while, but haven't shipped due to the pandemic. Apple is waiting for a time to release when people may actually want a device to locate lost objects, which isn't something you'd need if you are not leaving your house regularly. In his video, Prosser suggests a spring release is likely and his insiders agree.

'AirTags' image concept from Front Page Tech
Known leaker Jon Prosser has shared another video with some new details about Apple's missing Tile competitor. "AirTags" have been rumored since Apple introduced ultra wide band (UWB) to the iPhone 11 lineup.
The short clip shows the "AirTags" spinning in an animation similar to what is shown when pairing AirPods to your iPhone. This gives us our first 360 degree view of the device from an alleged official source. Prosser has provided concept images before based on leaked video, but this is the first time seeing the design in its final form.

The first look at alleged official 'AirTags' design. Image Credit: Front Page Tech
The design is simple with a white-rounded back and a silver front with an Apple logo. It looks similar to a watch battery with a slight hump on the back.
The "AirTags" will use other Apple devices in a private network to track down your lost device. Similar to how Tile works, user privacy and data will be protected.
Apple's U1 processor equipped with UWB is expected to be utilized in "AirTags" for location within a few inches of precision. AR location finding features have also been discovered in previous iOS versions.

Apple 'AirTags' tracking tool final design shown in animation. Image Credit: Front Page Tech
Prosser asserts that the "AirTags" have been ready to ship for a while, but haven't shipped due to the pandemic. Apple is waiting for a time to release when people may actually want a device to locate lost objects, which isn't something you'd need if you are not leaving your house regularly. In his video, Prosser suggests a spring release is likely and his insiders agree.
Comments
I'd like to know when the doorbell goes, how come there is only the cat there when I open the door. (I reckon he waits for the postman, who rings the doorbell if the cat meows at him).
To answer your question: they don't come when you call because they're ungrateful creatures. You can tell by looking at the state of your carpets.
Can you post these other "Bluetooth tags" that have all these features in the size and price range of Tile? I can easily see how larger equipment can be tracked at an airport with accuracy, but I can't see how those can be with easily pocketable devices whose batteries last for month. Airplanes use ADS-B Out to send their locations and that's not being used by ground vehicles at airport, but these aren't small, inexpensive, or using BT.
https://www.faa.gov/airports/resources/advisory_circulars/index.cfm/go/document.current/documentnumber/150_5220-26
https://www.digitalmatter.com/applications/bluetooth-asset-tracking/
Are you actually serious about that?
Uh, you're clearly mixing up the front and back.
All rumors point to these determining location from other users' iOS devices, which *checks notes* have GPS. Did you watch the video?
But your Homer Car device idea sounds really Apple-like. 🙄
Rumors suggest about the size of a bottle cap.
My guess is that it would be the iPhone 11 and up due to the Apple UI chip with UWB.
The compatibility is actually more down to a business and/or functionality decision rather than the tech itself…
In theory any device with bluetooth could be good enough; with some features that one might want to require starting with the iPhone 4S.
However, practically we are pretty much assuming that an AirTag-device would one way or another be related to the Apple U1-chip; which would mean the devices listed here: https://en.wikipedia.org/wiki/Apple-designed_processors#U_series_list.
What isn't listed there is of course the AirPods Max; which is where the guessing game becomes a bit extra muddled, and here's why. Since the AirPods Max has other features allowing it to keep track of where it is it appears like Apple won't make it a pure hardware-thingie to locate devices physically. So there seems like they're betting on an abstraction layer that sort of is technology agnostic. If that's the case they could potentially make the core technology available on any device compatible with the latest OS, assuming that's how they chose to launch AirTag-compatibility. Some devices would just not be able to show direction to the lost device, only distance.
So at the end of they day we don't really know until something actually is released; but "11 & up" seems like a safe bet when it comes to the iPhones.
Edit: By safe bet I mean that there's no reason to go upgrade in anticipation of an AirTag launch if you're currently on an 11 (or better) iPhone. But personally I'm on an Xs Max, and on the fence about the 12 Pro Max; and I would really like a Tile-like device leveraging the whole Apple ecosystem. So it could get expensive.
/s