Blackout Privacy Filter is designed to prevent unauthorized viewing on wide-screen monitors. Design helps ensure the privacy of on-screen data on your 24" LCD wide-screen monitor. Microlouver technology creates a narrow viewing angle so the image is only visible to those directly in front of the screen. Side view is black. Frameless filter overlays LCD surface for a built-in look. Filter also eliminates glare, increases contrast & protects LCD surface from damage. Aspect ratio is 16:10. Actual dimensions are 20-3/8" wide x 12-3/4" high.