This milwaukee part will be cut few mm below "red parts",
Attachment 16335
and connected to other brand batteries
Zrzut ekranu 2021-05-2 o 16.05.28.jpg
what finally give me something like this
Zrzut ekranu 2021-05-2 o 16.08.00.jpg


The point is I have few new milwaukee tools and one milwaukee battery, while I have a dozen or so other brand batteries. So this top part (milwaukee) should work like original or very similar.