Mirror Screen Protector for Samsung Epic 4G (Galaxy S) Sprint When the screen backlight is turned off: the screen protector can act as a mirror, you can enjoy high definition mirror effect When the display is turned on: the screen can be clearly seen and used as usual This screen protector can protect the LCD from scratch,if there is ash on it,you can erase it by a cloth ,the LCD can rechange to new. It will not affect the stylus using if you stick the screen protector on LCD.