Window Pivot Lock Shoe

Take a look at 15-195B. Is it the same as what you have? Does it have the "open cam," where you're able to see straight through the metal hole? If so, it's a match.

This belongs to a Series 795 balance, if you need the whole assembly. I'll include some videos on how to replace the shoe and the balance. The balance in the video is different, but the shape is the same, so it will still show you the basics of how to remove the balance.