BERSEM Fully Removable Privacy Screen Protector Compatible with iMac 21.5 inch Monitor Privacy Screen for Apple Desktop Computer, Filter Anti-Glare Anti-Scratch UV-Blocking 16:9 Ratio

The computer privacy filter makes the screen appear dark when looking at it from an angle (the angle is about 30°- 60°), but bright when looking directly at it. To change the privacy angle from 60° to 30° degrees - simply adjust your monitor’s brightness level. Also protects your eyes by filtering out 96% UV and curbing blue light by 65%.