Lock-in-place in-spool desiccant (silica gel) container with optional hygrometer

This model inherits the characteristics of PsychProd's original model: Fast print speed due to the clever basket design, great air permeability, and the option to add space for a hygrometer.

In-spool locking: The one thing that bothered me with the original model was that it would not stay securely inside the spool. It was fine when held firm in a vacuum bag, but if you took out the spool and handled it, you could easily drop the container. To solve this, I added a locking ring such that the container screws securely in-place and stays locked inside the spool when you move it about. This is especially nice because I like to use the containers to extend the desiccant capacity in the drybox / drier I print from. This solves the problem of the container falling out as the spool rotates.

Internal lid: I did not want to risk silica gel going everywhere when installing/removing the container, so I also added an internal lid to the design. This keeps the desiccant secure whether or not the external lid is screwed on.

Backwards compatibility: The original dimensions and threads are preserved, so these new parts are all compatible with the original model. If you have a few lids or containers of the original design, these will still fit them. Of course, they won't lock inside the spool unless both parts are the remixed version :)

Parts: There are two versions of the lid without space for hygrometers. This is because there is no longer any need for the external lid to contain the silica beads. Therefore, one version removes the external grid. However, this of course means that it looses backwards compatibility with the original model. Therefore, I also kept a version with the grid still in place, even if it is now unnecessary.

Parts included: 
- Small container with added locking ring and thread for the internal lids
- Large container with added locking ring and thread for the internal lids
- Lid for hygrometers with added locking ring
- Lid without hygrometer with ring and the original grid removed
- Lid without hygrometer with ring and the original grid preserved
- Internal lid that screws into either the large or small container
- Bonus: I have also included two funnels that attach to the internal lid threading and help you fill and empty the containers.

The small container + hygrometer lid or the large container + non-hygrometer lid fits a standard 1kg filament spool. The internal lid is optional (but recommended), unless you use the non-hygrometer external lid without the original grid.

Costs and speed: For the standard configuration fitting a 1kg spool with hygrometer and internal lid, this upgrade takes about ~11% longer to print and costs an extra ~7g of filament with my default slicer settings. In my opinion, well worth the investment.

V2 edits: In response to feedback, I've enlarged the vents in the locking ring that it does not block air diffusion in spools with a tight fit. I've also added vents to the hygrometer so that it better measures the surrounding air, not just the desiccant.


Acknowledgements:
- @PsychProd: If you like this design, please leave a like or something for the original designer. He/she also has an affiliate link for hygrometers that will fit, so consider using that.
- @rfengr_1: I took inspiration from rfengr_1's locking desiccant container when designing this. I didn't use any of his/her files, but I marked this as also a remix of his/her model because my design uses the same solution and principal aesthetic, and I felt that he/she also deserves credit.

I really liked PsychProd's container, but I found it annoying that it would always fall out of the spool when I handled it. Therefore, I added an external locking ring such that the container screws securely in-place inside the spool. I also added an internal screw-in lid so that you do not risk spillage when removing the container. Retains backward compatibility so you can mix and match as you please.