The 50.8 cm (20 inch) [443 x 250 mm] is a measurement used to describe the size of a screen protector that is compatible with a range of devices with a 20 inch display. Our website sells a variety of screen protectors that are designed to fit this specific size, providing customers with a range of options to choose from. By using this measurement, customers can easily identify which screen protectors are suitable for their device and ensure that they are getting the right fit for their screen.