The 48.3 cm (19 inch) [377 x 302 mm] measurement refers to the size of the screen that the screen protectors on our website are designed to fit. This size is commonly found on desktop computer monitors and some all-in-one computers. By providing this information, customers can ensure that they are purchasing a screen protector that will fit their device properly and provide the necessary protection against scratches, smudges, and other types of damage. Our website offers a range of screen protectors specifically designed for this size, allowing customers to choose the one that best suits their needs and preferences.