A easier to make, sturdier, and more hassle free filter fitted for GOST threads. You can easily print this on standard settings, and it fits most if not all Russian masks due to the GOST threads. You can fill it with cotton or something else to filter out large dirt particles, dust, and the like but I can't guarantee you can make a working filter with this. This new design includes a protector of the filter cans to keep cotton and fabrics in so you can keep large dust particles from building up inside. To assemble the Lid and Can you just glue the top and bottom together with epoxy, superglue, hot glue, anything that will stick. I'm sure it can be printed with almost any amount of infill, but I prefer 30-50% infill.
Another feature is a little groove to put stickers into.