They're great when you want to block wandering eyes that might be able to see what's on your desktop monitor.The thin privacy screen limits the field of vision to +/- 30 degrees and attaches with tab holders you place around the edge of your screen. Kensington K55796WW FP200 Privacy Screen for 20" Widescreen Monitors - For 20" Widescreen Monitor - Fingerprint Resistant, Scratch Protection With the Kensington K55796WW FP200 Privacy Screen you will be able to protect the sensitive information displayed on your monitor while also protecting your vision and the screen itself from scratches and fingerprints with a Privacy Screen for a Widescreen Monitor.