This is a remix of the Milwaukee M12 Battery Cap with Screw Hole which is a remix of Milwaukee M12 Battery Cap (v1). I added an additional screw hole spaced 1 inch apart because if found the single screw version would rotate. The additional screw keeps it in place better.
I actually modified this part privately a few years ago. I found myself needing a few more and I dug this up. I figured I'd post it in case other people found it helpful and give the original designers credit.