Screen Expanders & Magnifiers by Fanlory. Details:More and more people use their smartphones to watch videos or movies, however, it gets incredibly uncomfortable to watch a small screen for longer periods of time, and it can even damage your vision. If you often watch videos and movies and are tired of uncomfortably staring at a small screen, our screen magnifier is perfect for you. Featuring an HD zoom optical technology, the screen magnifier magnifies your screen at two times its size, retaining a crisp and clear image, without the need of a battery. The viewing distance of the amplifier is 1-3 meters. 2. It can't be seen under strong light (ambient luminosity). 3. The brightness of the screen of the mobile phone is brighter and better. These 3 factors are important to achieve the high-definition effect.