security window stop , stops window from fully opening

Thanks for reaching out! The part you are searching for is the window vent latch. I believe yours is our 26-122 Vent Latch. Take a look over the dimensions to confirm.

Diagram of 26-122

I'm sorry to say that I do not believe there are any other parts you can use in place of what's already installed there. It is typically recommended to use a 1 to 1 replacement.