As Vine Voice, I tested the K&F CONCEPT double-sided magnetic filter clip in combination with the included 58 mm CPL filter on the iPhone 17 Pro. The adapter is clearly aimed at users who want to get more out of the iPhone camera photographically — and it does just that. Thanks to the strong magnets, the filter clip sits very firmly and securely on the back of the iPhone. Nothing slips during normal use, and installation and removal is quick and easy. First images taken with the CPL filter show a visible improvement when lighting conditions are right: reflections on non-metallic surfaces are reduced, colors appear richer and the sky is significantly more structured. The effect is particularly visible when photographing landscapes or architecture. I find the compatibility with standard 58 mm screw filters particularly practical. As a result, you are not limited to one filter, but can flexibly expand the setup — in my case, the next step is an ND filter to also take long exposures with the iPhone. The included storage bag also makes a high-quality impression and is suitable for transport. A small downside: When combined with an iPhone protective case, the filter clip does not fit perfectly. For the best fit, the case usually has to be removed, which you should plan for everyday use. The bottom line is a well-thought-out, high-quality accessory for ambitious iPhone photographers who want to use their mobile camera consciously. Anyone who is willing to forego the case for a short time will get a powerful tool for visibly better pictures.