I received the new X-PRO filter set today and have already tested its applicability in the apartment. I'll give you a verdict on the quality of the filter glasses and how they can be combined in one shot... The box supplied holds the holder + adapter rings + CPL + ND 8/64/1000. The compartments can be pulled out on the drawstring and the filters can then be removed very easily. The plastic filter frames are discreetly sharp-edged, but not uncomfortable, and allow the filter to be removed and handled without having to touch the glass. Thanks to the tabs on the frame, the filters can also be pulled out of the holder very easily, especially in any order. I ordered two empty frames in 100 X 150 from the manufacturer's website, which should hold my graduated filters, which I have from another manufacturer, upon receipt. I'm curious how well this works. If it works, then I have a complete system for myself, with CPL, three ND filters and two graduated filters (Soft 0.9 and Reverse Soft 0.9). Sliding the filters in and out of the holder requires some force, but isn't awkward or imprecise. In this way, the graduated filter will also be easy to align. The handling of the CPL filter with the insert bracket is great, the turning mechanism is a bit rough, but precise. Screwing the adapter rings onto the lens works very well, the threads are cleanly worked, so nothing rubs. Attaching the holder to the adapter ring is also a joy and the presence of a set screw is very welcome as the holder rotates on the ring with relative ease. The handling of the system has already convinced me, I can live well with "only" two slots for my needs and I'm looking forward to the first use, in the next few days, in the great outdoors and with cold fingers. So far I've worked with round screw filters and dispensed with gradient filters, which I would like to change now. I also looked at the system from Rollei (Mark II), which cannot keep up with the handling of the X-PRO from K+F. Everything is very flat and fiddly, offers hardly any contact surface for holding and assembling the parts. Getting the polarizing filter or adapter ring out of the holder is no fun and almost impossible with cold fingers. K&F solved this much better. If you want to use gradient filters, the X-PRO set is a good choice. If you only need gray filters, I would recommend a magnetic round filter set with a diameter that is significantly larger than your largest lens, which is even faster to use, is more compact and should then do not darken with several filters in parallel.

It attaches easily and does not allow direct light to enter between support and lens, I am delighted with it, very easy to put on and remove and the filters are of very good quality.
I recommend it for people who are demanding in photography, very good quality.

very good quality. I'm happy.

For a while I had been hesitating between several brands to choose a filter holder for ND and GND filters. I took advantage of a flash sale to buy this kit. I am not disappointed.
The set seems sturdy and easy to store.
The case, quite pretty, has 5 compartments, 3 of which, for square ND filters, are raised via a ribbon. On the back of the case, there is a belt loop and a belt loop. I would have liked a slightly more spacious compartment to house the adapter rings with the CPL filter when it is removed.
The assembly (or disassembly) of the elements is well explained in instructions in several languages, including French.

Main positive points:
No dominant color, nor loss of sharpness on the first tests carried out.
The plastic frame with its tabs to handle ND filters.
The system for installing the PLC filter on the filter holder.
the knurled button for mounting the adapter ring and for rotating blocking the filter holder.
The very accessible wheel to control the polarizing filter.
The sturdy holding of the square filter on the filter holder.
The robustness of the metal filter holder.

If you have to find slightly negative points: Keeping
the square filter a little too sturdy in the filter holder.
The click too loud to lock the CPL filter in the filter holder.
No pouch to independently protect the CPL filter in the case.
No protective cover for the CPL when the set is installed on the lens.

Very high quality ND1000 K&F Concept square filter set consisting of glass filter, filter holder and lens adapters for the filter holder.

The package is divided into 3 parts:
1. a bag with metal adapter rings for lenses with different diameters.
2. a box with the filter and its leather carrying case.
3. a box with the filter holder.

The adapter rings allow us to put the filter holder on any lens, since we have a large number of different diameters. They are made of black metal and well made. With inscription on each ring of the corresponding diameter.

It is a square filter ND1000 100x100 mm and 2 mm thick. It allows us to remove 10 light levels to make long exposures in daylight perfect. In the example photo I posted, it is taken at noon at 30 ". I love the play that can be taken from this filter.

The filter comes in a leather case and is covered with tissue paper. The case is sturdy enough to protect it properly.
The glass is not easily marked by fingers and does not attract dust.

The filter holder is metallic, with the part where the filters rest being made of some kind of very hard plastic. They easily fit two 100x100 filters

I received the new X-PRO filter set today and have already tested its applicability in the apartment. A judgment on the quality of the filter glasses and the combinability in a shot I still deliver ... The supplied box holds the holder + adapter rings + CPL + ND 8/64/1000. At the drawstring you can pull out the compartments and then very conveniently remove the filters. The plastic filter frames are decently sharp-edged, but not unpleasantly so, and allow you to remove and handle the filter without having to touch the glass. The tabs on the frame also make it very convenient to pull the filters back out of the holder, especially in any order. I have ordered two empty frames in 100 X 150 on the manufacturer's site, which should take my graduated filters after receipt, which I have from another manufacturer. I am curious how well this will work. If it works out, I'll have a complete system for myself, with CPL, three ND filters and two graduated filters (Soft 0.9 and Reverse Soft 0.9). Sliding the filters in and out of the holder requires some force, but is neither awkward nor imprecise. This will then also allow the graduated filter to be aligned well. The handling of the CPL filter with the insertion bracket is great, the turning mechanism is a bit rough, but precise. Screwing the adapter rings onto the lens goes very well, the threads are cleanly made, nothing rubs. Attaching the holder to the adapter ring is also a pleasure and the existing locking screw is very welcome, as the holder can be rotated relatively easily on the ring. The handling of the system has already convinced me, with "only" two slots I can live well for my needs and I look forward to the first use, in the next few days, in the great outdoors and with cold fingers. I have so far worked with round screw filters and waived graduated filters, which I now want to change. I also looked at the system from Rollei (Mark II), which can not keep up with the X-PRO from K+F in handling. Everything very flat and fiddly, offers little surface for holding and joining the parts. Getting the polarizing filter or adapter ring out of the holder again is no fun and almost impossible with cold fingers. K&F has solved this much better. Who wants to use graduated filters is very well served with the X-PRO set, who only needs gray filters, I would advise a magnetic round filter set, whose diameter is well above its largest lens, which is even faster to use, is more compact and should then not darken with several filters in parallel.

very easy to use

Takes a bit of getting used to but the value of a top quality holder, ND filter and a circular polariser complete with several adaptor rings makes this a bit of a bargain. I can even use it on my 14-30 NIKon Z Len’s at 14mm without vignetting once positioned correctly. Pretty impressive bit of kit. The ND is excellent and neutral. Recommended!

I mounted the kit on a lens with the 72 mm ring and it fits perfectly. It's easy to assemble and its operation is very simple, it doesn't require reading the instructions (I'd say it's better not to read them) just seeing the illustrations is enough. As for the quality of the product, it seems to be made with good materials and the finish is excellent; the polarizing filter holder is very effective, placing the filter well and with care and you don't touch it at all. There are two compartments for the square filters that I hope to get the most out of, I'm happy.
As for the optical quality of the filters, I can't comment because I haven't used them yet.

I had been hesitating between several brands for a while to choose a filter holder for ND and GND filters. I took advantage of a flash sale to acquire this kit. I am not disappointed.
the set seems robust and easy to store.
The case, quite pretty, has 5 compartments, 3 of which, for square ND filters, can be lifted by means of a ribbon. On the back of the case, there is a ring for passing a strap and a passage for a belt. I would have liked a slightly more spacious compartment to house the adapter rings with the CPL filter when it is disassembled.
The assembly (or disassembly) of the elements is well explained in a manual in several languages, including French.

Main positives:
No color cast or loss of sharpness on the first tests carried out.
The plastic frame with its tabs to handle the ND filters.
The CPL filter installation system on the filter holder.
the knurled knob for mounting the adapter ring and the rotating block of the filter holder.
The very accessible wheel to control the polarizing filter.
Firm hold of the square filter on the filter holder.
The robustness of the metal filter holder.

If you have to find some negative points:
The slightly too vigorous maintenance of the square filter in the filter holder.
the click too hard to lock the CPL filter in the filter holder.
No pouch to independently protect the CPL filter in the case.
No CPL protective cover when the assembly is installed on the lens.