3M Privacy Filters keep confidential information private. Only persons directly in front of the monitor can see the image on screen; others on either side of them see a darkened screen.
From the Manufacturer
Notebook privacy filters keeps confidential and private information private. Utilizes 3M's patented microlouver technology so only persons directly in front of the monitor can see the image on screen, passersby see only a blank, dark screen. Unique attachment system, stays in place even when monitor is closed. Lifetime warranty.