Measured the part at 1 3/8" inch by 3/8 inch.
Hopefully the 4 attached photos will help. This is the piece that holds the extension arms on to the bottom of the awning window frame of my American Craftsman window. There are two awning windows in this privacy bathroom window. Both of the Parts broke very quickly. I believe I will need to get several to be sure I have some should they break in the future. Thank you so much for your assistance.