Best Cat Access for Sliding Windows now available in many sizes.  Simply attach the Insulated Panel to the top of your window frame using a small strip of hook - Then attach the top of the Panel with the pre attached loop to the newly installed hook.  Then attach the flap and close your window up next to the installed panel.  That's it.  1-2-3 and you're done.  Now your Cat has a way to safely come in out of the cold and be safe.  Custom sizes available.