Expansion bay interposer.
So I can close the internals. And install after keyboard reinstall??
This page should cover most questions: Framework | Using your Framework Laptop 16. If you have not changed the expansion module you should be fine. While you have things apart it may be worthwhile to confirm that the interposer screws have been tightened - but don’t overtighten them (my comments, not Framework official guidance, afaik). Enjoy the machine!
Full guides are here Framework Laptop 16 - Framework Guides
That’s the interposer for the blank / fan-only Expansion bay shell.
If you have a GPU Expansion bay module installed. Then the GPU interposer should be installed. Guide Install Graphics Module - Framework Guides. You do not need the interposer you posted a picture of at this time. Just save it and keep in its case (the pins are delicate).
If you installed a blank / fan-only Expansion bay shell, then you must install the fan interposer, before the keyboard. Instructions are here Install Expansion Bay Shell - Framework Guides
Thanks for the assistance.
Marking as resolved.