It's just a filter element in a can. I cut my Xterra's open and found very fine particles(not many just a hair(not from the cutting, different color and it wasn't metal). I took a razor and scraped against the filter media and brown sludgy/boogery residue was on the blade.
5 years, 35k miles, I think it was due for the Filter change. Filter didn't age well either, taking it off it was a solid rust ball except where the bracket wrapped around it.