Small shim that has a little tab that can be used to remove easily. Is meant to be used with this design by dkarjadi.

Similar to the way my top glass plate was able to move around slightly without the led riser mod, there was still some wiggle once I finished installing the mod, so I designed this tabbed shim that has removed any play at all on the top.

I printed this in TPU just like the pieces for the mod itself, haven't tested with anything like PLA, would probably work but the shims would need to be put into place before you put anything else on the top. In TPU I was able to push the shims in easily.

See attached picture for how I installed them.