Hello, thank you for posting,
To further review, we will need to see the window open where we can view the operator arm(s). With the window unlocked, you should be able to gently push open the sash to expose the arm(s). From there we can determine the overall style your window uses for a compatible handle. Thank you!
Thank you,
Your window uses an older Roto operator style that uses the 39-226 handle that has a 5/16" pro drive hex. This handle will only work if the collar in the base that the handle fits into is still intact and not damaged.
The operator arm uses the 39-541 track slider to connect to the sash track.
If you are interested in replacing the full operator, please start by reviewing the 39-400 or the 39-430 depending on the arm length. This upgraded operator is compatible with the 39-232 folding handle.
Please review and let me know if you have any additional questions!