Admittedly, the system of magnetic filters is not entirely new and I cannot say who copied from whom, but I already know K&F from their very good lens adapters and solid tripods. And since I've been flirting with magnetic round filters for a long time, but up to now the prices for such a system have seemed too steep to me, I was of course interested that K&F now also offers something like this.

For the price great, i reaaly like it.

As a photographer, I use filters, but it's not always easy to put on or take off depending on the situation. But with this system, it becomes so simple that it's almost instantaneous.
The product is of very good construction quality and it comes with a very well made and resistant 4 pocket pouch against possible knocks. It can be attached to the belt with a Velcro. The kit is composed of two screw rings, one UV and one vacuum on which the CPL filter or the ND1000 can be fixed.
I really wanted to go and test this new product. First with the CPL filter alone and then with the CPL filter + the ND1000 together. The results are just astounding. Here are the renderings with the CPL filter on the left and the CPL + ND 1000 on the right. With the filters, there is no loss of sharpness, and color drift is almost zero. The CPL filter polarizes perfectly and the ND 1000 filter is very surprising in terms of its performance, it is very thin which limits vignetting, a plus. By using the two together, it is better to avoid ultra wide angle focal lengths, but from 16mm, no worries, you can add them. In addition, they are compatible with my sun visor, I was able to put them on and take them off without having to take them off very easily because the magnetic force is perfectly dosed.
Really very satisfied with this first release, I hope that other intermediate magnetic filters with this system will be released soon to complete the offer.
If there were magnetic lens caps, that would be awesome.
It is a very good investment and the price is more than correct given the quality and the results obtained.

As a landscape photographer, I found this filter system really interesting. Unlike screw filters, these filters can be applied and removed in a fraction of a second, while unlike plate filters they are much less bulky, lighter and, of course, much quicker to install. The K&F Concept Nano Series magnetic filter kit is extremely practical. The case containing the filters is compact in size, which allows us to carry it in our backpacks with very little space sacrificed.
The weight is extremely light, which is really useful for long excursions where the weight of the equipment starts to be felt after several hours.
The installation and removal of the filters is lightning fast, to say the least; in a matter of seconds you can easily fit all three filters and, in just as many seconds, remove them.
The holding power of the magnets is really good and therefore there is no fear of finding yourself with filters that fall during shooting or transport.

There is nothing to say about the quality, they are excellent for the price they have.

These are so easy to use and the quality is fantastic - both the build quality and the picture quality. I can't see any colour cast whatsoever from both the CPL & ND filter. I think you would really need to pixel peep to see any sharpness difference, and even then I'm not sure there is.
Being able to attach the filters to both the UV filter and filter ring is really clever - I keep the UV on my 24-70 F4 and the filter thread ring on 16-35 F4 so it makes it even faster to clip on the filters no matter what lens I use.
Since the ND isn't variable, there's no dark X. And no vignetting at 16mm, unlike when I use my square filter set.

The downsides that I see at the moment:
- You can't replace the filter thread on its own, so if you break or lose it, you have to buy a new set.

Very suitable for shooting silky water. High quality glass and threads are indispensable for any serious photographer.

Dommage que les accessoires pour réutiliser les filtres que l'on a déjà soit si difficiles a commander.

For the price of one I now have a well made variable ND filter for all my lenses - I am very pleased!

The filters appear to work well in testing. I would not trust them to remain on the camera when in the field. The magnetic mount is not strong enough. Fine for tripod use and then take the filters off and put them back in their case.