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.
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. Designed to fit standard laptops with a diagonally measured 12 3/16" viewing screen and a 4:3 aspect ratio. Actual filter dimensions are 9 3/4" wide x 7 5/16" high (247 mm x 186 mm). Includes your choice of two easy-to-use attachment methods. Reversible, matte side reduces glare and reflections. Lightweight, thin, frameless design. Protects display from dirt, debris and scratches. Cleans easily with a soft cloth and water. Great for high traffic areas such as airports, airplanes, commuter trains, coffee shops and other public places. Limited 1-year warranty.