I've used the filter several times and it works great plus the mount works great and have already used other filters with it...

Apart from the fact that it is an excellent product, the customer support is absolutely great, I have rarely been treated so reliably and friendly, big praise.

Since I haven't worked with ND filters before, I don't know what I could complain about here.
Overall I am very satisfied with the glasses from K&F. You get a high-quality, processed filter with top optical quality and a good scope of delivery (artificial leather case).

The filter does what it is supposed to do, it extends the exposure time. I haven't noticed any vignetting or wrong color reproduction so far. And so I'm satisfied. The packaging of the filters is very good and practical, which some higher-priced filters can't do that well.

Ich war länger auf der Suche nach einem Rechteckfilterhalter und wurde nach längerer Recherche bei diesem Anbieter fündig.Der Halter wird mit 7 Adapterringen mitgeliefert und lässt sich somit an verschiedenen Objektivdurchmessern befestigen.Der Adapterring wird auf das Objektivgewinde gedreht und der Halter einfach auf den Ring montiert.Die Halterung hält sicher und gibt mir keine Bedenken, dass sie nicht halten könnte, auch wenn sie minimales Spiel hat.

Very easy to use system. The picture quality is really good as far as I can tell. The polarizing filter works very well. Thanks to the adapter, the filter can be used on any lens. Have never regretted the purchase.

Good quality of the filter.

bought the rectangular filter set directly from K&F. Since I have worked with screw filters in the past and had the problem with vignetting when screwing several filters on top of each other, I have wanted to buy a rectangular filter set for a long time. Since the sets from NISI, Haida and other well-known manufacturers are very, very expensive, as a hobby photographer I was looking for a cheaper alternative. When I saw several reviews on YouTube, I decided on the K&F set, which is half the price of Haida and CO. I have absolutely no regrets about my decision. The filter holder is very valuable and well thought out. I particularly like how the polarizing filter is attached to the holder and how it can be adjusted using the small wheel. The filters themselves are made of optical glass and show no color cast and are also well coated. Another positive aspect is that the filters have a plastic frame with a tab. This allows the filters to be inserted and removed without annoying fingerprints. A bag is included to store and transport the holder and the filters in it. Also included are various adapter rings for different filter thread diameters. As a landscape hobby photographer, I no longer want to do without the advantages over screw-on filters. I give a clear purchase recommendation for amateur photographers and professionals too! I wasn't expecting such excellent quality for this price. It's amazing what K&F delivers here.

Finally found an ND filter which can be installed inside the Smallrig lightweight matte box 2660. I did have to remove the holder frame to make it fit. This can be done by carefully pulling appart the frame sides with the lips. In doing so you can op out the filter while keeping the frame intact. Filter quality seems to be ok and it comes with a very well designed holder with an extraction ribbon which avoids having to touch the surface of the filter when taking it out.

Simple to swap out filters as well as adapt to a wide range of lens diameters.