This is a through-hole screw mount for a [EEEkit Hygrometer](https://smile.amazon.com/gp/product/B07BLY177S/) (Amazon link, non-affiliate). You can use this to mount a humidity sensor for readability outside a container, but with the sensor inside.
This was designed so I could easily view the humidity inside the sealed storage container which contains my filament.
You can easily snap the hygrometer into the "outer" casing; it'll hold tight as it has tabs on the inside. Is it a perfect seal? Definitely not, but it's not bad. I printed the casing in PETG.
Included are gasket should be printed twice; these were printed in TPE, so they're a little squishy.
The Fusion 360 `.f3d` is included in case you need to make any modifications. I'll attach photos later, once it's installed.