oil/water filter for floor drain?

[Piper]

I've seen, but can't seem to find now, an insert that you can put into a floor drain that acts to remove the occasional oil spill. It was a filter of some sort which fits into your standard 4" big "o" drain pipe. Does anyone have a link or direction on this? I need one as I indicated to our bylaw officer that I'd use it and he's passed my floor drain on the promise that I have one of these things.

Thoughts?

Piper