I like to take photos with my dSLR camera. Unfortunately, sometimes I don't have it with me and I take photos with my smartphone. To be able to be a little more creative, I tried this ND filter on my iPhone 15 Pro max. The filter holder holds various filters with a size of 52mm. When the iPhone is used without a case, the holder completely encloses the cosmic lenses. Although the holder is of course visible from the front, Face ID unlocking is not affected, which I find very positive. The setting options on the ND filter itself are seamless within the specified range. This allows you to take creative photos. Of course, other filters with a size of 52mm can also be used. It would also make sense for me to use CPL and star filters as well as close-up lenses. The fact that I can now use other filters alone improves the iPhone camera a lot and I'm sure I'll be able to take nice photos in between without having to lug the "big" camera around with me all the time. By the way, I already know the company K&F Concept from various filters for my dSLR lenses and have always been satisfied and convinced by them. In any case, for anyone who wants to get more out of their iPhone shots and the unlimited possibilities for using various other filters make the product a must! for photographers who want to create something more than standard images.