I made a filament drybox out of cereal storage containers (I used these: https://www.amazon.com/gp/product/B07NP98YKY) and Pneumatic PTFE fittings (I used these: https://www.amazon.com/gp/product/B01KHN1HWY). I designed this nut that fits the inside curve of the container near the top. I printed them in ABS filament.