Window sash shoe connecter?

Thanks for writing in. This looks like a pivot bar. It fits into the pivot shoe in the window track, thus allowing you to tilt the window in for cleaning. We may be able to replace this for you, but we'll need to see an undamaged version of the pivot bar out of the window. If you could measure the distance between the center of the mounting holes to the tip that fits into the pivot shoe, that too would be helpful. From there we'll narrow down what we can. In the time being you can view our selection of pivot bars here.