Certainteed Brand Security tabs
Hello! The part you're looking for is called a vent latch, or sometimes vent lock, or night latch, or anything in between. Every manufacturer has their own name for these parts. Either way, yours in particular looks like our 26-148. I recommend going over our photos and dimensions to see how well it compares.
You will eventually have to remove it, though I don't think that can be done without breaking it. I know that seems weird, I think the manufacture figured you'd never have to replace it. Or, more likely, that you'd be forced to buy an all new window from them instead of just this tiny little part. Since you have to force it out, just be careful not to damage your frame as well. The video below should help.
Thanks for getting back at me. Yes, this shouldn't matter. I'm confident the 26-148 will work for you. Let me know if you have any other questions.