Developed by qualified optometrists, these medically-rated screen protectors for smartphones and tablets effectively block up to 99% of harmful UV & blue light emissions between 300-400nm and up to 40% of harmful blue light between 400-470nm. The result is a crystal-clear display and a healthier, more productive you! Blue Light penetrates your retinas, giving your brain a cue that it’s time to wake up and seize the day. But extended exposure to blue light from your mobile phone can have a significant impact on our well being with headaches, eye irritation and fatiue all being common sympoms of blue light exposure. Not only that, but blue light restricts the production of Melatonin (a chemical which helps us sleep). Features and Benefits Prevent Eye Strain - Accredited Class 1 Medical Device by the MHRA Durable - Super-strong tempered glass to protect your screen. Sleep Better - Improve sleep and protect your eyes with our blue light filter. True Colours - No retro orange tinge, a crystal clear picture. Specifications Colour: Transparent Length of Guarantee: 12 months Design & developed by Optometrists in the UK Suitable for: iPhone 11 Pro Max/XS Max