Just the Drawer!
This is the same drawer that ships within the Full and Half-size Tower Cases (included with the bundle cases). This is offered as so that you can have more than one drawer in your case. When adding an extra drawer, you place it on top of an empty display board.
Why add an additional drawer? They are very handy. One example is if you want to make your Half-size Tower Case into a painting hobby case; now you have room for a bunch more paints, brushes, and other hobby supplies. For game play, some people like have a drawer full of vehicles rather on trays. So, there are options...