Missing. Parts to open windows
Thanks for reaching out! It appears the worm gear in the center of your window operator has become stripped. When this happens, the entire mechanism needs to be replaced.
To make am accurate recommendation, I'll need to see a photo of the entire operator. I'm specifically looking to see photos of the operator arm(s) and how it attaches to the bottom of the swinging window sash.
Please don't hesitate to reach out with any other questions you might have.
We can supply you with the replacement operator you need but I'll need to be able to see the entire mechanism to identify it, as requested. The operator is stripped, so replacing just the handle will not resolve the issue.
You'll need to open the window to obtain the photos I've requested in my response above.
Thanks for the additional photos. Your window operators can be replaced likely be replaced with the 39-031 and 39-032 EntryGard Dual Arm Operators. You'll need to carefully compare the dimensions to confirm that these are the correct fit for your window.
I've tagged the compatible hardware and accessories below, in case you may need to replace those as well.
The sash lock reminds me of the 38-100 RH Truth Lock Assembly. Take a look over the diagram below to see if this is the correct replacement for your window.
The left handed version is the 38-099.
