There are two plastic sliders for the side curtains.  One pin from each side broke that are suppose to provide sliders to the bottom of the unit.   They don't fit flat in the notch underneath.  You need to put in  the side curtain screws in before you put the unit in the window.  The screws grab one of the plastic curtains unless you spend time moving the fold from the screw.  I only needed them to expand a few inches.