Reduction for gas mask filter

CAUTION: USING ONLY AT YOUR OWN RISK! THIS PARTICLE IS NOT APPROVED AND TESTED!

Gas mask filters reductions 40x4mm to 40 x 1/7" (tested by my self and work fine!) and 40 x 1/7" to 40x4mm (not tested). There is short or long "male" thread versions and brim or no brim versions.
I printed this with 5 perimeters and 5 up/bottom layers. Gaskets i make from rubber 25x37.5x2mm.

Production and use only at your own risk!

Thoroughly choose the material for real use. ABS is probably the best one. PLA or PETG can be dangerous in to the house fire where the temperature can be too high!