replacing Truth 11 series operator

I'm sorry our website failed to accept your photos. Awning operators like the 39-348 use different screws depending on the window. If it's a wood window, they will use (QTY 4) #10 x 1.0 Phillips Flathead Metal Sheet Screws, like our 33-079. If it's PVC and metal windows, you'd need (QTY 4) @10 Phillips Flathead Screws; the length and thread type would be determined by the profile of the window, and so consulting a local hardware store might be best if you're in doubt. 

See the videos below that detail how to install a window operator. While different designs in both cases, the principles demonstrated might be useful for you. 

Hello! Your operator looks similar to our 39-083. This may be what you want, but you should check the "elbow to elbow" measurement to verify that it's the same. That will let you know for sure.

Dimensions for 39-083