PF19.5W9 fits widescreen Monitor computers with a diagonally measured 19.5" (495.3mm) viewable screen; actual filter dimensions are 9 7/16" high x 17" wide (240.28mm x 431.8mm). This filter is designed for widescreen monitors with screens that appear more rectangular than square and have a 16:9 aspect ratio. Desktop monitor privacy filters keep confidential and private information private. Utilizes 3MT microlouver privacy technology so only persons directly in front of the monitor can see the image on screen; passersby see only a dark screen. 3MT PF19.5W9 Privacy Filter provides more effective privacy than competitive filters and offers more consistent quality and uniform appearance, thus reducing visual distractions.