The SA215 Privacy Screen Filter for iMac 21.5" helps protect your privacy, simply and easily. A washable, reusable adhesive makes installation - and re-installation - a breeze, with no unsightly bubbles. Protects privacy by limiting viewing angle to +/- 30°. Reduces harmful blue light by up to 22%, diminishes glare, improves clarity, and protects from scratches and damage. Includes anti-bacterial cleaning cloth.