I had actually used the Neewer ND filters for my DJI drones and GoPro for years and was always satisfied with them. Now I've also received this one from K&F for testing my new Mavic. The delivery was done quickly thanks to Amazon.

The filters fit the Mavic 3, as is also available from Neewer. In terms of price, the two sets are not much different. K&F are a few euros cheaper, but also offers quasi-integrated polarization filters. The filters are all well made and sit firmly on the camera housing. Even with lots of action and turbulent scenes, you don't have to worry. The filters remain reliably in place.

The ND filters extend the exposure time in bright sunlight and the pictures simply look much better than without them. There are some good apps that recommend specific ND filters depending on location, season and sun position/time. Lens flares are also largely suppressed when shooting backlighting, which Neewer also does well.

The lenses are easy to clean and come with a case for transport. I can only recommend it. If you are looking for ND filters and don't need the polarization settings, you can also use Neewer. Neewer is on sale from time to time, but unfortunately I don't know about K&F yet. Since they're new to me.