21.5''5 wire resistive touch screen

 5wrie resistive touch screen is a two-layer structure, two materials (film or glass) with ITO are attached with a gap between them so that the ITO layers are facing each other. Touch input will be made as the top layer is pressed down and the two ITO layers contact. There are insulators called spacing dots between the top and bottom ITO layers. These spacing dots prevent unintended contacts (inputs) of the ITO layers when not pressed. 
    When the top ITO film is pressed and makes contact with the bottom glass, the contacted area will be detected via electrical conduction. The notable characteristic of 5wire resistive is that only the bottom glass has detecting function. Even if the top ITO film is damaged, the detecting function will not be affected (except for the damaged area).