That means yours is the large case feeder, ideally for .45 ACP. I have both sizes, so I know what I am saying.
after looking at the OPs pics i see that the EXTRA piece is a round counter. LOL. no wonder why i dont have it.
i will order the "small" inserts for the case feeder tubes, but it does have the small case pusher that loads the cases onto the shellplate.
I tried to post pics of my mods but this board will not allow shutterfly pics to be posted i guess.