I have seen these before, but for the life of me I cannot seem to recall what they are called or what they’re for.
Google search - especially image search, where I’m trying to bring up similar items - is now a total potato and seemingly capped at one screen of results in a secure and sanitized browser.
At work I use similarish D-sub connectors @ 40A/pin, 3 pairs => 120A @ 12V.