Keep your filament dry with this simple spool holder designed to fit up to an 8" spool in 4L air tight cereal boxes. There is a cutout in the front for a mini hygrometer to track the humidity and temperature of your filament. There is space behind and underneath the spool to fit your preferred desiccant. I personally use 100g reusable packs slotted behind the spool. Follow the affiliate links below for the exact containers and hygrometers used in this project.
I was able to print this with no supports on my P1S. There was some minor sag under the overhang, but this is covered by the hygrometer. You can print up to three at once on a 256x256 bed.
4 Pack - 4L Air Tight Container