I was thinking they attach to something or something attaches to them via the hole you can barely see and a dowel type handle is "twisted" into the hook thingies to quickly lift it and then remove the handle. I was also thinking the colors hold some clue..... You have two basically neutral colors that go with anything in white and black, and you have two high visibility colors. That was making me think along the lines that this is a consumer used product and not a manufacturing one. Don't ask me why. I was even thinking along the lines that it's kind of rope cleat to quickly hook and unhook the rope from.
And again, I was also thinking along the lines that Andy should throw us some kind of bone