Can you elaborate on this a bit. Your mention dwv in the title,
dmv above. Are you looking for a plumbing DWV vent cap???
Why not have a lookdown installed. Could still get a snake in if needed.Doing a particular restoration job for a client, client has requested a vented cap / guard for the dwv pipe on the roof to avoid vandalism by concrete, sand or debris. Sorry I just noticed my TYPO.
I've seen galvanized metal vented caps, any additional ideas?