3M™ Safety & Security Window Films also help you deter crime. Because the window film improves the integrity of the window, the criminal is slowed down to such a degree that they may choose to move on to an easier target. The S70 and S80 are single layered films having thickness of 7 mil and 8 mil, whereas the S 140 and S 160 are multilayered films having thickness of 14 mil and 16 mil, respectively.