Vinyl Window Latch

I'm afraid I can't tell what you have without seeing it removed from the window. Too much is obscured. That said, it does look like you might have an Andersen window. Consider our 90-288 and 90-289, or the opposite hand 90-290 and 90-291. Check to see if there are any labels or tags on the window frame or any etching in the glass itself signifying what brand window. 

If this hardware will not work for you, we'll need you to remove it and show us a picture of the mechanism by itself.

I'm afraid seeing a close up doesn't confirm what you have. The only way we can confirm is to see it fully out of the window. The parts I mentioned are similarly designed, and I think they're worth considering, but I cannot guarantee they're what you have.