PF23.8W9 fits widescreen Monitor computers with a diagonally measured 23.8″ viewable screen; actual filter dimensions are 11.69″ high x 20.77″ wide. 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 3M™ microlouver privacy technology so only persons directly in front of the monitor can see the image on screen; passersby see only a dark screen. 3M™ PF18.4W9 Privacy Filter provides more effective privacy than competitive filters and offers more consistent quality and uniform appearance, thus reducing visual distractions.