The screen comes standard to fit onto a window so it needs to be cut down to fit our smaller cubes. The good thing is that it already comes with an adhesive on one side so make sure to take advantage of that! Once you have the right width and the desired amount of wrinkles for the length, stick the adhesive side to the inside edge of one side. Apply adhesive onto one end of both magnets and stick one onto the middle of the last fold and the other to the middle of the opposite internal wall. Make sure the screen is straight then allow to dry completely before using.
To keep the screen open, a clip or another magnet can be used. The magnet would be glued to the same fold that is glued to the box. Make sure the magnets are strong enough to fold the folds together.