This design is a vacuum filtration system to adapt standard 50mm filters on filtering flasks.
It adapts of flasks with a 34mm opening (43 OD opening).
This design uses 2 o'rings 43 mm OD, 36 ID and 3.5 mm thick to ensure a good hold on the filter. You can use a third o"ring (same dimensions) to get a good seal against the filter flask but in my experience it is unnecessary with most air pumps as little air passes though the gaps.
6 M3 screw 20mm long and 6 nuts are used to hold the filter together.
The base has two version: the standard version and another one with a funnel. The funnel prevents the solvent from going into the pump but it is more fragile and hard to clean.
This print contains single wall features so make sure you use the Arachne wall generator, activate the "detect thin walls" or similar relevant option depending on your slicer.
Just make sure the solvent you are filtering is compatible with the material you use to print the filter.
Alternatively orings you can print the join out of TPU, the file is among the STLs.