The 3M Notebook Privacy Computer Filter uses patented 3M microlouver technology to make on-screen data visible only to persons directly in front of the monitor. Passersby can only see a dark, blank screen. Your screen view remains sharp and clear with improved contrast and privacy without blurring. It's anti-static and is easily attached and removed. The filter stays in place even when the notebook is closed. The filter is compatible with 17" widescreen laptops and LCD screens.