— the presence of a window in a flip or other element (for example, the wall of a bag) that covers the screen. The window allows you to see the notifications on the phone's display, and can even be used to work with the touch screen — more precisely, some of it, of course, but the shape and location of the window are usually selected in such a way as to provide access to the key features of the device. The window can be covered with a transparent film — this increases the degree of protection, but worsens the reaction of the screen sensor (up to the complete impossibility of using it). The absence of a film, in turn, has a positive effect on the quality of control, but part of the display remains completely open.
