RetinaGuard Anti-Blue Light Screen Protector for iMac21.5 - SGS & Intertek Tested - Blocks Excessive Harmful Blue Light, Reduce Eye Fatigue and Eye Strain 90% blue light blockage (380nm-420nm) / 98% UV blockage (310nm-380nm) Reduce blue light damages and protect the screen / Zero color distortion / Anti-scratch 9H hardcoating SGS & Intertek tested / Japanese technology / manufactured in China / Easy no bubble installation, no residue Excessive blue light exposure found in LED screens may lead to imbalanced melatonin levles found in sleep disorders and eye strain and fatigue We understand the potential harm of excessive blue light exposure in children and adults who actively use LED devices and take great pride in achieving the necessary requirements to ensure that RetinaGuard is the highest performing and most trusted blue light Screen Protectors on the market