I call it a "d-ring holder"...since it holds the d-rings on the Jango holster rig...and have made more than I'd like to remember (50-give or take a few).
I searched high and low for a handle, thingy, anything made of aluminum, fiberglass, resin, etc. that had the accurate shape (1/2 round top, flat bottom) and the closest I came was an aluminum handle to a pair of garden cutting shears from Target. But it still wasn't accurate enough because it was about a 2/3 round top.
So, I make my own out of 1" pvc class 200 pipe and 1/16" styrene sheet. Glue the two pieces together, trim, sand, primer, sand, R&B, and glue it to a piece of leather to be screen accurate.
Here are a few pics that might help you in your build. I think the accurate width is somewhere between 2.25"-2.5", but I usually make mine about 2.75" to accomodate taller heights than Temura's.