We cannot see any identifying marks on the broken one. As you can see it has split and part of it is missing. I hope that the photo of the window which is still intact will be helpful in identifying the part. Our amateur description is that it a plastic clamp that holds the pivoting bar in place. It is approximately 1.5 x 1.5 inches And is held in by two screws on one side.
Thank you for your help.
Bobbi and Ed
