What is this?

I know, do you?

The answer is: This is the tension assembly from a 60s/70s vintage Singer Sewing Machine. That's obscure enough that it wasn't a very fair question.

[Brian]

A wigwom for a goose's bridle? That's what my late father used to say. LOL
A clutch?
Well displayed

[Larry L]

@briaan Wigworm for a goose's bridle" gets top points for originality!

[Diane]

A fishing reel?

[Larry L]

@eudora nope, but I can see how it might be. But the whole item fits easily in the palm of my hand

[jackie edwards]

A spark plug🤷‍♀️

[Larry L]

@jackies365 Nope, though it does have a similar shape.

@briaan, @eudora The answer is: This is the tension assembly from a 60s/70s vintage Singer Sewing Machine. That's obscure enough that it wasn't a very fair question.