0382752|SCREEN DOOR BUBBLE SLIDER PANEL (RH/CLEAR) FOR 5055RC STYLE ENTRY DOORS
here is the vendor info. DEXTER VENTLINE/DEXTER DOOR|4812-01
Above is per chat with Thor rep Jason (online).
They seem to be pretty helpful.
I'm asking Pacific RV parts if it is an item they can get. Will report back. Mine was missing it on delivery. I'm asking the dealer to get one, but this might get it to me faster. Won't hurt to have another.