its for an awning window

Thanks for reaching out to us. I'm afraid I can't make out the arms from this photo alone. The 39-096 and 39-176 come to mind though. I recommend you review the specifications of each and see how they compare with your old assembly. Please note that these parts are designed for casement windows though it looks like this window was adapted to be used as an awning window. 

Let us know if you note any discrepancies. 

Dimensions for 39-096

Dimensions for 39-176

Alternate view with measurements