I have a slim casement window for the bathroom. The glass window comes with two levers which you use to push the window outward & open.
I keep the window open for perhaps 10 degrees, the equivalent of 1 inch at the widest part (opposite the hinge location). It stays that way in warm weather. I keep it shut during winter.
What options do I have, when I keep the window partially open ? I would like to know both the hard-to-install ones, and, those that are easier-to-install but probably also easier to be tampered with. The purpose is to make it challenging for an intruder who tries to get in from outside through this bathroom window.
I have a screen placed on the bathroom side to keep bugs out.