The idea of creating filters for mobile phones with a magnetic holder instead of with clips is a great thing both for easy use and handling, as well as because of the changing system. The quality of the filter is also undoubtedly excellent. In addition, the set comes with a case and a cleaning cloth, which allows the whole thing to be neatly stowed away. I can't see any edge shadows or distortions during the recordings, which speaks for the flawless workmanship. I can't confirm the heating of the phone mentioned several times here, but I don't use the polarizing filter for longer video recordings, but mostly for photos to make the colors look stronger and reduce reflections. What I can confirm, however, is that the use of the filter including holder is not really possible with protective cases with a slightly thicker protective frame around the camera, here you have to remove the protective cover to allow perfect use of the filter, which I find rather cumbersome, and nullifies the principle of simple use by attaching with a magnet. A protective case with a built-in filter holder would have been better here. For this, a star deduction for the actually good product.