I just got really into upgrading and playing around with different parts on my reels and this came up: I ordered a drag star from a zillion type r however it didn't come with the piece that slides into it which sits between the handle and the star. What is this piece called? Thanks in advance.

Sounds like your talking about the handle collar or the click leaf spring holder...

I'll take some pictures later and post them, it's almost like a washer that fits over the main gear shaft and into the drag star if that helps explain it

The schematic will show a part number and sometimes name for each part. I recommend never attempting to work on a reel without one in front of you.

And the handle collar it is! Thanks to you both for the assistance. Now, what exactly does this piece do? Purely a curious question, I'm not really working on the reel, just replaced the handle. It was a simple detach reattach operation

It's a spacer to keep the handle from rubbing directly against the drag star when completely loose.  You can clearly see it's function by looking at the schematic.  It rests on the notch of the narrow threaded portion of the crank shaft, where the handle, handle nut tighten down on that narrow spot.

Thanks again everyone for the timely responses!