These simply cover the opening to the XY stepper motors to protect them from dust and debris. Simple print, snaps in place and helps keep the motors safe. No supports needed.
I've remixed the original to use a little less material, resulting in a slightly lower profile, but increased the tab size/strength. Because of that I've also added indentations on the top to make removable super quick with a finger tip so if you need to get in there for some inspection its simple.