Advantages1. The camera is small and can be carried easily.2. The battery usage time is long.3. Easy to select menu.4. It is waterproof.6. The price/performance is good.Disadvantages1. In 1080 60fps shooting, the pixels are coarse than expected, and the sharpness of the screen is poor. 2. The zoom function is meaningless because it is not an optical zoom. Conclusion: Good for beginners to use.(After using more, I will add a testimony.)

My set of Mavic 3 Classic ND filters attaches easily and comes with a neat protective case. Testing the ND64 filter I got a noticeable 1000K Cool/ 2% Green tint color cast, but the spectrum transmission is smooth so it can easily be corrected in post. The sharpness is good. Overall happy with the filters, especially for the price.

The K&F Concept ND filter set is rated in ND 8, 16, 32 and 64 for DJI Mavic 3 Classic.

The filters come in a small plastic storage case. Inside are the 4 filters, embedded in a foam rubber mold. Thanks to the foam rubber, they remain reliably in place and are well protected from scratches.

The filters themselves consist of a metal frame and tempered optical glass.
They are included in 4 different strength classes. For most purposes, the filters should be sufficient to be able to increase the shutter speed of the drone as desired, thus creating a cinematic motion blur in the image. Or simply to be able to correctly expose the image.

The filters have a very good workmanship. They fit the drone's lens with millimeter precision. The closure of the filter holder snaps gently into place. The filters can also be easily turned down again.
I really like that the filters are made of metal. In addition, one weighs just 8g, which does not change the flight characteristics of the drone.

The compensation is excellent, the filter has no color cast.

Conclusion
In my opinion, the K&F Concept ND filter set is a very good product. The filters are cleanly processed + the set is thoughtfully put together. Long exposures with ND256 or higher filters will not be done from the air anyway, so I think the ND 64 is the all-purpose weapon for very bright environments or very long shutter speeds for motion blur.
At the time of my review, the price of the filter set was around EUR 50, which in my opinion represents an excellent price/performance ratio.
So I'm giving it 5 stars and I hope my review was helpful.

The Mavic 3/Mavic 3 Cine Drone variable ND filter is well made, easy to install and use, and nicely packaged. Compared to filters bought on other platforms, K&F does a great job!

I had actually used the Neewer ND filters for my DJI drones and GoPro for years and was always satisfied with them. Now I have also received this one from K&F for my new Mavic to test. Delivery was quick thanks to Amazon.

The filters fit the Mavic 3, which is also available from Neewer. There is not much difference in price between the two sets. K&F are a few euros cheaper, but also offer quasi-integrated polarization filters. The filters are all top-quality and sit firmly on the camera body. Even with a lot of action and turbulent scenes, there is no need to worry. The filters remain reliably in place.

With the ND filters, the exposure time in bright sunlight is extended and the pictures simply look much better than without them. There are some good apps that recommend certain ND filters depending on location, time of year and position of the sun/time. Lens flares in backlit shots are also largely suppressed, which Neewer also does well.

The lenses are easy to clean and a case is included for transport. I can only recommend. If you are looking for ND filters and do not need the polarization settings, you can also use Neewer. Neewer is occasionally on sale, unfortunately I don't know about K&F yet. Because they are new to me.

The ND filters for the DJI Mavic 3 Classic drone of excellent workmanship, very easy to install and use and with excellent packaging.
I use it with my drone and the difference is remarkable. It eliminates digital over-sharpening, reduces contrast and allows you to reduce shutter speed. good investment

I mainly shoot video with my Mavic Air and as any video professional knows, shooting with a 180 degree shutter angle is usually ideal. That means shooting 4K30 at 1/60 second, but in full daylight that's impossible without an ND filter. These tiny ND filters do what they're supposed to and produce no noticeable color cast (I didn't take any side-by-side, but didn't see anything noticeable). It took me a while to figure out how to install them ;-) but once I did it was easy. (You need to remove a piece of the drone's lens first).

I'm pretty impressed with these ND filters. First off, the build quality is pretty good...metal frame and glass construction, as opposed to the cheaper plastic versions (that I've had before). The picture quality is great in my opinion. Check out the short video for yourself. Shot on Mavic Mini (original) with ND32 filter 1080p at 30 fps and ISO 100. I also have another brand (Freewell) of ND filters for my Mavic Air 2 and I find that they work just as well as this one (obviously different drones... but compared to image quality) and are a bit cheaper. These install easily and stay on securely. I would definitely recommend these.