The 38.4 cm (15.1 inch) [306.2 x 229.8 mm] measurement refers to the size of the screen that our website sells screen protectors for. This size is commonly found in laptops, notebooks, and other portable devices. Our range of screen protectors is designed to fit this specific size, providing protection against scratches, smudges, and other types of damage. By choosing the right screen protector for your device, you can ensure that your screen stays in pristine condition for longer, extending its lifespan and improving your overall user experience.