Just rotate the funnel in your slicer... put the 120mm side down, filter facing up. Flip the top cap piece as well, so the flat side is facing down. Not sure why they imported that way.
Use this filter to get rid of nasty ABS fumes. Use in conjunction with another filter (below to get the best filtering for your printer.
I made the fan side oversized so it would be easy to put some type of gasket to seal the enclosure. I just used some vinly tape (electrical tape) cut to fit to make a gasket.
Recommended to use with the Activated Carbon filter on one side of the fan, and then this HEPA filter on the other side, at relatively low fan speeds it completely got rid of the odor in my room from ABS.
The hepa filters its made for:
the 86889 style filter.
I recommend using these as well:
Cut them to fit this adapter:
I used some #6-32 screws cut to length to secure the cap.