3M Touch Privacy Filters provide world-class “black out” privacy from side views outside the 60 degree viewing angle, while creating an excellent viewing experience from straight on views. Designed for full screen monitors with flat glass displays, these privacy filters are reversible between a glossy side & a glare-reducing matte side that helps reduce reflections & hide fingerprints, so you can enjoy pristine image clarity. Diagonal Monitor Size: 21.5"; Fits Device Type: Dell OptiPlex 3240 AiO or 5250 AiO; Mounting Details: Adhesive Strips; Filter Material: Polycarbonate.