3M Black Privacy Filters utilize ingenious microlouver technology to deliver world-class effective privacy for laptops and monitors. Side views are “blacked out” from prying eyes while your screen remains clearly visible to straight-on views. 3M Black Privacy Filters fade to black starting at the 30-degree side angle, are reversible between a glossy side and glare-reducing matte and reduce 35% of blue light transmission. Diagonal Monitor Size: 20.1" Fits Device Type: For Widescreen Monitor Frame Type: Frameless Mounting: Attachment Strips Slide Mounts.