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. You can pull out the compartments on the drawstring and then remove the filters 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 after receipt, that I have from another manufacturer. 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 waited a bit before buying compared to other brands today I don't regret a very good product

After a good six months of use, I can say that the system serves its purpose very well.

Regarding the filters:
The image quality of all filters is excellent and a color cast is minimal even when using 3 filters at the same time. The polarizing filter reliably reduces reflections and leads to a crisp contrast.

Regarding the holding system:
When the polarizing filter is screwed in and the rectangular filter is attached, there is no rubbing, the polarizing filter can be operated perfectly.

I was completely satisfied.Darken the scene 10 light levels so you can take long exposures in daylight in total comfort. It is made of glass and looks good quality. I used.Comes with a leather case, lined with a soft fabric inside; velvet type which comes very well so you can wear it without fear of scratches.

After many reviews that I looked at on Youtube, I decided on the new K&F filter holder and have not regretted it so far. It is easy to use and makes a very high-quality impression. The use of the CPL filter is a great solution. Lever up, put it in and lever down again, done. Adjusting the wheel is also buttery smooth. In contrast to the first K&F filter holder, the filters, which now have a frame, can now be pushed in very easily. Not too easy and not too heavy either. A clear buy recommendation.

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 bought this because the kit provides me with the variety of filter mounts I need to cover my lenses. I have not seen any problem with unevenness or color streaks in my images. Focusing is a challenge, of course, due to the filter density. The mounting rings attach securely to my lenses and the connection between the rings and the filter holder is solid. My filter fits firmly in the holder. I suggest inserting the filter into the holder "off camera." Screw the appropriate mounting ring onto your lens, and then "click" the filter/filter holder combination into place. While still holding the camera in one hand and the filter holder in the other, try to wiggle it or pull it off to test that it is firmly attached and that it won't fall off while you are shooting.

I loved the quality of the materials, all metallic. I looked at many kits but they were all plastic and this one in particular caught my attention from the comments. The truth is that it was a success because any other similar kit does not fall below 300€.The nd1000 optical filter is made of glass and gives a very good quality. The only thing I noticed is that it loses a bit of saturation and the white balance is a little bluish, but when processing the RAW it's easily remedied. You increase the color temperature and saturation and you're done!! (I use a Canon 80d + 16-35 f4's). I imagine each optic will be different. Attached some photos so you can see the difference with filter and without filter. Exposure time on the photo with the 30" filter. If you want to start in the world of filters, for this price don't even think about it. Excellent results.

excellent filter system. Very easy to use. Ordering from k&F Concept is easy. Highly recommended.

To be honest I was really hesitant to purchase this, however the price intrigued me enough to give it a try. I have to say this ND Filter is right up there with the best. It comes nicely presented and the case to store it in is great. There have NOT been any weird coloration in. The glass is high quality and easy to clean. Honestly I love this ND Filter.