Ok so the hole in the center along with the setscrews on the edge suggest it fits on and is tightened onto a shaft. Maybe like a weedeater, or maybe something electrically driven like a ceiling fan.
Luv, I deleted your last post. Sorry, some days I am dangerous to have mod authority. I had been mindlessly editing your post when I was trying to respond to it and I made a mess of it. I think the thing is the adjustable shaft collar that holds the blades on a fan.
