The 54.1 cm (21.3 inch) [433 x 325 mm] is the screen size of a specific device for which our website sells a range of screen protectors. This measurement is important for customers to know as it ensures that they purchase the correct size of screen protector for their device. By providing this information on our website, we aim to make the purchasing process as easy and convenient as possible for our customers, while also ensuring that they receive the best possible protection for their device's screen.