I tested the K&F Concept filters on a Canon EOS 5D Mark III with a Canon lens.
I am very satisfied.

The filters are very well made. They are delivered well packaged. It is also practical that you get them right away in a well-padded bag and can thus store them well protected in the photo backpack. So the filters can also get no scratches and you always have the filters of one size together.

Also supplied is a cleaning brush.

The filters are absolutely accurate fit. This is not self-evident for filters of this price category.
I received the filters on a test basis which has no influence on my rating.

Original photos

Its perfect for my Canon EOS M6 mark II with the 22mm lens and the Canonb EOS RP with the 35mm lens ... I was amazed from the quality and the compact size ...

Got this for my "nifty fifty" Canon 50mm 1.2 L lens on my Canon 5D Mark IV, and they're pretty solid.
You get three filters: (1) ND4 (2) CPL and (3) MCUV which are all pretty useful in different scenarios.
A huge plus for the included case, soft brush, and price point.
Overall, I would recommend this for any creator doing photography BOTH indoors or outdoors, and looking to significantly reduce reflectivity!

I used this filter on my Canon Rebel T7 with EF-S 18-55mm IS II lens and a size larger adapter. It works beautifully, crystal clear, screws on with ease. It comes in its own hard case with a cleaning cloth.

I ordered this filter for my Canon M50 Mark II lens and it fits like a glove. The material of the filter is metal and robust. The coating on the lens ensures more realistic colors. I recommend it as an addition to your camera equipment.

I use this adapter on my Canon M50 Mark II and am satisfied. The old EF-L/S lenses can be used with it. That makes you want to keep using the old old lenses. The autofocus works without problems. Only the adapter is mostly made of plastic, but this has not affected the functionality so far.

Works well on my Canon M6 Mark II mirrorless. Would have given 5 stars except the mounting lock doesn't engage so it's too easy to twist slightly. When rotated, the lens opening is prevented from narrowing to the set aperture.

In perfect condition. I fit great with my Canon Mark II. The focus is on the hand