What is pipeline?

I am trying to animate an ammo clip like the health pickup.Floating and rotating. I managed to get a rocket to do this, but I seem to be missing one thing for the ammo clip…pipeline! What is it,and how can I get it?

251229--9048--$rocket_821.jpg
251229--9049--$ammoclip_173.jpg

Pipeline is an old obsolete component; just delete it.

–Eric