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.

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 are well made. Labeled on each ring with the appropriate diameter. The filter holder is metallic with the part where the filters go made of some kind of hard plastic. Two 100x100 filters and 100x150mm gradients fit easily. The system of attachment to the adapter ring is via a very manageable metal tab. In several tests that I carried out 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 which is very easy to correct when editing, but it's not exaggerated at all. I am very happy and enjoying it very much. I recommend it!

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.

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.

With this adapter I can use all my Nikkor or Nikon lenses on the Fujifilm E-X1. However, it is necessary to set the “Shoot without a lens” option in the menu, otherwise the shutter button will not click. The diaphragm is closed by the intuitive ring. I tried it with a G Sigma EX 1 lens; 4-5.6 with 10-20mm focal points (equivalent to 15-30mm of a full frame): The ring allows you to close the aperture while maintaining full aperture for manual focus, from 24cm to infinity. Of course, the Fuji ring works better for Leitz M lenses, since it is enough to set "adapter" and focal length and any distortions can be corrected. But it costs more than ten times as much. Focus is obviously done manually as with digital and analogue Leica Ms. The courier was unable to deliver on the scheduled day, claiming that "no one was there". Instead we were all there. Saturday to Monday. Then don't complain if Amazon will use drones.

I first attached the magnetic adapter ring to a 77mm lens and it threaded onto the lens extremely smoothly. I then switched on one of the filters and once it was close enough to the adapter ring the magnetism took over and it jumped onto the adapter ring.

I found that each one was magnetic and I could easily stack all the filters together - just to prove the magnetic force was strong and good enough to keep the filters attached to the adapter ring.

Overall I think it's a good value - and although the principle works, changing filters quickly using just the magnetic rings.

Adapter is solid and well made. I love the button on the back for removing the ring off a lens. It's much easier to use than the metal tab some other adapters have. The only small inconvenience is not being able to switch lenses on the camera without having to remove the adapter as well, but the button allows for switching lenses relatively quickly without much fiddling.