Hi there!
These clips hold the window screens in place using a plastic screw. The clip has a tab that fits into the window frame. All windows in our house use these clips. Have not been able to find a replacement. Either plastic or metal would be acceptable. House was built about 20 years ago. These are the original windows. There is no marking on the clip. The label on windows is "Vinyl King".
Hope you can help!
Thanks!
Bill in Boise Idaho.