***** **********Best Quality Guranteed. *****This Blue light screen filter is designed to fit 20 Inch (Diagonally Measured) Monitor, please compare your monitor size to the listing image on the left*****Filter out Blue Light and relieve computer eye strain to help you sleep better*****Block 99% of UV and block the harmful blue light between 380nm - 490nm*****Easy Installation and removal. *****Protects screen against scratches