The 4Vu Privacy Screen is designed to fit 19” LCD monitors with 5: 4 ratio screens. To protect your information, tiny vertical blinds on the surface of the privacy screen narrow the viewing angle so data is only visible directly in front of the monitor up to 30° away from the center of the screen. Onlookers will only see a dark unclear screen when attempting to view the information from a side angle. In addition to providing security, The screen also blocks the glare to help reduce eye strain.