Sleeve at Neutral Bar

Anyone seen those pop rivet type sleeve at the neutral bar? 1970 built home with aluminum wiring. Sorry about the quality of the pic.

I can’t see what you are referring to.
Put a pointer at it.

Are you referring to bottom left holes numbers 4-5-6 starting from the left?

Blurry but looks like a bunch of double lugging. With three of them as pointed out by Robert as having some kind of connectors.

Yes I am.