Balance shoe for tilt window

I'm not sure exactly what I'm looking at here. It looks like it might have come out of a pivot shoe, perhaps something like our 15-191. I'm not sure, though. 

I can tell you that whatever you have here in this photo, we probably won't be able to replace it by itself. If this came off of a larger part or mechanism, there's a better chance we can replace that instead. If the 15-191 isn't a match, show me what this hardware fell off of and we will do our best to find something better.