This blue light blocking screen protector blocks blue light up to 70%, effectively protecting your eyes and easy to install and clean. Feature: Blue Light Filter  It blocks blue light up to 70% to effectively protect your eyesight. Why do You Need it? If you suffer from dry eyes, eye fatigue, reducing melatonin, ultraviolet radiation, freckles, wrinkle or myopia, you need a blue light blocking film to protect you. The Necessity of it We have to use computer for a long time while cornea and crystalline lens of our eyes are unable to resist or reflect blue light. What’s more, blue light may cause maculopathy which to some extent speeds up the process of losing sight. Easy to Install There are 2 ways to install, choosing the one you prefer --- either hang it up or paste it onto the screen. Screen Protector The surface is matte-finish to effectively resist grease, fingerprint and sweat. Specification: Material: PET Item size: 527* 297* 0.39mm/ 20.75* 11.69* 0.02in Package size:  540* 340* 3mm/ 21.26* 13.39* 0.12in Package weight: 256g/ 9.03oz Packing list: 1 * Blue Light Blocking Screen Protector 1 * Installation packet (Double-sided tapes, Slide adhesive tabs, Cleaning cloth)