Alcan window closing mechanism
Hello! This looks like an awning window operator, specifically our 39-070. I believe this is the part you want, but make sure to review our dimensions to verify that they match up.
You mentioned that your current operator doesn't close the window as tightly, but I think that has less to do with the operator and more to do with the fact that your awning window is installed sideways. This operator is meant to be at the bottom, which tells me that whoever installed this window likely bought the wrong style, but installed it anyway.
There's not much you can do about that, unfortunately. This kind of operator isn't meant to be on the side of the window and so there is no alteration or change you can make to make it do its job more effectively. You will either need to make do with what you have, or buy a replacement window that's properly oriented.