[seningen]

Is it metal? Is it ferrous? Maybe part of it is plastic?

I'd guess chain, chain guides, or paddles wear based on the picture.

Note your IMS rests in a plastic cradle as well as a shoulder/hip type socket
on the far end -- so if its going but somehow hasn't completely failed it
can wear against these surfaces -- but I can't imagine it would be long for life
under those conditions.

There are several points where chains ride against plastic paddles
and there is metal behind some of the paddles.

I'd try to figure out what it is -- but either way that level of debris does not bode well.

Mike