Product review (4 stars): Drastically decreased odor from my outdoor septic vent.
Seems to be doing the job. Occasionally I still get a whiff of odor, but it is drastically decreased over what it was.  At the moment I haven't cemented together the PVC elbows of the filter itself as I wanted to be able to take it apart if needed. Perhaps cementing will remove what little odor is still present.  As I said in my review of the seller, their customer service was GREAT. I had some confusion at first as to the best way to connect this to my outdoor vent and they were very patient and helpful.