The base of your operator reminds me of our 39-037, 39-069 and 39-070. Review the dimensions for each and compare them to yours to see which one matches up to your old assembly.
A quick learner from AK says:
June 3, 2022
When it says 20-1/2", is that the length of the lever length (end to end) when the window is almost closed?
Emily from SWISCO responded:
June 6, 2022
That measurement is for when the window is closed so you'll need to remove the operator from the window completely for an accurate measurement.
