I am working with a Sony Zv e10 mark ii and a Sigma 16mm. There is really no reason to get something more expensive. It fits perfectly, records excellently without noise and without affecting the colors. The best value for money in my opinion.

I wear them on all my lenses, mainly for protection. They are of excellent quality, despite their low price (just like the CPL/ND filters from the same company). Sturdy, thin, and their glass does not distort the image at all, nor does it darken it.
Of course, like all filters, they occasionally produce a bit of flare in direct bright light. A small downside, compared to the dirt and water they have taken instead of the lenses themselves.
Additionally, since they are not made of brass, it is good not to tighten them too much, as they may get stuck (this can be fixed with a little force or a small screwdriver).

Also, it is worth noting that KF has amazing after-sale support. If you have questions, they respond immediately. If any problem arises, which the seller does not address, they step in and resolve it without much fuss (replacement or refund).

It is worth a lot both in terms of quality and for its price. Before buying it, I read on various sites that it makes no sense to buy a filter with glass worth 10-15 euros when you have a much more expensive lens that has very good glass quality. However, I have been using it for a short time now and there is absolutely no difference in quality. You take exactly the same photos with exactly the same quality, you just protect the lens. I highly recommend it.