The K&F Concept universal cell phone camera lens set is perfect. I'm often by streams and especially around midday the shots are always a bit bright.... I've often heard that you can get a lot more out of an ND filter. The clamp holds the filter securely over my P40 Pro, even with a thin case. The filter can be easily adjusted with the clamp. Since you can adjust the filter, you should take the time to experiment a bit. It's worth it! I was able to create much better saturation. It comes in a sturdy, sealable plastic case and can be stored in my gimbal bag. I'm very satisfied. For me as a YouTuber, it's an inexpensive, simple improvement in video quality. Happy to give it 5 stars.

I am absolutely thrilled with the Concept Universal Lens Set for mobile phone cameras. The ability to vary the ND filter from ND2 to ND400 offers incredible flexibility for all lighting conditions.

I am a passionate landscape photographer as a hobby and have now switched from the screw filters to this rectangular filter system from K&F. The screw-in filters were all fine, but you don't have the option of attaching a graduated filter to the ND filter in order to achieve even nicer effects.
It is mounted on the lens using so-called adapter rings, which are included in the most common sizes for lenses.
After attaching the adapter ring to the lens, the filter holder is attached. This is secured by a small lever (spring-loaded) and later released again with this.
Now you can slide the filter plates into the filter holder. This lifts a bit severely but it should also hold and must not wobble.
It is also important to observe that the filter used is close to the lens so that no more light can penetrate between the filter and the lens, which could possibly ruin the recordings.
In terms of quality, the system makes a good impression considering the price. The only thing I noticed negatively is that the filter holder has some play after it is placed on the adapter ring and why there is no adapter ring for a 55mm filter diameter in the set, I also ask. 55mm is a common diameter for lenses.

I can highly recommend the K&F system for amateur photographers. The professionals will probably use filter holder systems from other manufacturers, but they also cost a lot more.

I bought the filter holder system together. The adapter rings cover all possible lens diameters, are made of metal and fit perfectly. Because of the tight mechanics on the right, I always equip the actual filter holder with plug-in shafts for a maximum of 2 filters before locking it on the adapter ring, which is less fiddly. The holder can be easily rotated so that it can be slanted, but it holds well and does not slip further by itself. The filter itself is also very secure and has to be pushed with force, which, however, secures it against falling. At the price maximum purchase recommendation!

I was looking for a rectangular filter holder for a long time and after a long search I found what I was looking for from this supplier. The holder comes with 7 adapter rings and can therefore be attached to different lens diameters. The adapter ring is screwed onto the lens thread and the holder is simply mounted on the ring .The mount holds securely and doesn't give me any concerns that it might not hold even with minimal play.

Filter is perfect. Great results for a good price.For me the only disadvantage is the very big universal filter box my 52 mm filter came in. Unpractical for compact travelers

The adapter rings allow us to place the filter holder on any lens, as we have a large number of different diameters. They are made of black metal and well finished. With labeling on each ring with the corresponding diameter.The filter holder is metallic with the part where the filters go from a kind of hard plastic. Two 100x100 filters fit and 100x150mm gradients without any problems. The attachment system to the adapter ring is via a very manageable metal tab.In several tests I did under different lighting conditions, I did not notice the entry of residual light through the space between the filter and the filter holder. The photos have a slight magenta tint that is very easy to correct when editing, but it is not at all overdone. I am very pleased and enjoy it very much. I recommend it!

am a passionate landscape photographer as a hobby and have now switched from the screw filters to this rectangular filter system from K&F. The screw filters were all fine, but you don't have the option of attaching a graduated filter to the ND filter in order to achieve even nicer effects. It is mounted on the lens using so-called adapter rings, which are included in the most common sizes for lenses. After attaching the adapter ring to the lens, the filter holder is attached. This is secured by a small lever (spring-loaded) and later released again with this. Now you can slide the filter plates into the filter holder. This lifts a bit severely but it should also hold and must not wobble. It is also important to observe that the filter used is close to the lens so that no more light can penetrate between the filter and the lens, which could possibly ruin the recordings. In terms of quality, the system makes a good impression considering the price. The only thing I noticed negatively is that the filter holder has some play after it is placed on the adapter ring and why there is no adapter ring for a 55mm filter diameter in the set, I also ask. 55mm is a common diameter for lenses. I can highly recommend the K&F system for amateur photographers. The professionals will probably use filter holder systems from other manufacturers, but they also cost a lot more.