cast iron pole topper ball

This thing came along several years ago now -- one of those (oh so many?!) sorts of things from the 'you want that? take it!' category.

It is almost 8"h x 5"w, and would fit comfortably onto a 4" pole of some sort. What exact sort of pole I don't know. Made of thick cast iron and hollow inside as seen (pic3) it still probably weighs ~15 pounds.

Maybe one of these days I'll find some-something pole to put it on top of, in the meantime it simply adorns my back steps railing as a faux newel post where, oddly enough, it has never been bumped or blown off...?? ;-)