[NAME] , that should be it.  You can also use this adapter, it's a lot cheaper.
I can't seem to find a M.2 SAS Flex Bay Module for my 7820 desktop. I want to add another SSD to the FRONT Bay does anyone have the Part # for that? They should be like this but for the 7820. [URL] 
Dell 7820 M.2 SAS Flex Bay Module?