It is a latch on a Certainteed window that keeps the window from swinging down for cleaning. The one on the right side is fine; the one on the left is missing, but you can see the 2 holes where its tabs will be inserted.
Casey from SWISCO responded:
October 28, 2020
Hello, thank you for writing in! Take a look at our 26-317. Compare its dimensions to yours to see if this could be a match!