Features: 1.UV Protection: The computer screen eye protector filters out harmful blue light and harmful UV light with wavelengths between 380 to 420nm 2.Blue Light Blocking: Blue light blocking technology keeps your eyes, sleep and skin from the negative effects of overexposure to blue light, reducing eye strain 3.Easy to Install: The blue light computer screen filter is easy to install, just remove the film on both sides of the blue light blocker on the computer screen after cleaning the monitor 4.Convenient and Practical: The 21.5in blue light screen protector is not easy to produce bubbles after hanging on the monitor, and can also be removed at any time and used on other computers 5.Acrylic Material: The computer screen protector is 21.5in monitor compatible and is made of high light transmittance acrylic to prevent dust and scratches. For broad HEV protection specification:Item Type: Computer Screen Eye Protector Product Material: Acrylic Applicable To: 21.5in for IOS Desktop (Approx. 330 x 537mm / 13.0 x 21.1in) Filter Wavelengths: 380 to 420nm Blue Light (beneficial light is not filtered), UV 99% Protection Easy to Install, Prevent Eye Fatigue, RGB Color Supports Self Color PackageList:1 xComputerScreenEyeProtector1 x Clean Cloth1 x Wipes2 x Anti Slip Stickers