We had some interesting guesses and a few were kinda close.
One of our readers was close...it is actually an industrial piece.
What you're looking at came off of an old street light. This heavy piece (and it's twin around the other side) would be bolted around a street light post - likely where two large vertical pieces of metal came together.
A peephole in to a radiation room was my favorite guess....we wouldn't want to have that kind of risky item in the store for fear of something like this happening again!
Here is another peek at the item.
What the... What?
Leave a comment if you know!