Maintains the full visible Colors of your LCD or LED Monitor. Easy installation. Prevents eye strain, CVS, chronic injuries to the eyes, eye fatigue, soreness and more serious eye related conditions. Improves sleeping patterns. For screen diagonal 19 to 20 inch measure only your screen diagonal without the plastic frame. Product dimensions: W 17.3 inch / Height: 10.8 inch. 100% Multi-Layer protection - Eliminates Hazardous UV spectrum and Blocks Harmful HEV light from your 19 inch and 20 inch monitor screen. The Best Anti Blue-Light optical grade product. Blocks Harmful Bluelight between 380nm~480nm.