Having used and been annoyed by screw-on filters for years, I was excited to try this magnetic filter system by K&F. I'm kind of a fan of their products, they often seem to find the right balance between quality components and yet still being a good value.

I came back to edit this review because initially I found myself disappointed in the design of the circular polarizer/variable neutral density filter. The way they arrived in the box, the ND filter was stacked under the circular polarizer. Turning one would force the other to turn and both filters could easily be bumped off of the lens.

Reversing these, which is how they are supposed to be, means the CPL goes directly on the lens/magnetic adapter, and next the ND. Yes, the CPL and the ND filters can be separated. You can adjust the CPL to where you need it, and then there is a small tightening knob to prevent if from turning. There is a groove on the CPL where the ND magnetically sits, keeping it secure, and also creating hard stops when you turn the ND from minimum to maximum. This way, both filters stay magnetically secure, the CPL stays put where you've adjusted it, and the ND filter can easily be adjusted as needed. It works very well.
There is some other good news, the magnetic lens cap and the black mist filter do seem to hang on tight to the magnetic adapter ring.

The included case is nice, holds all the included filters, has a bright orange interior so you can actually see what's inside.
The filters have a bright orange band and clear lettering to let you know which one is which.

If there are any criticisms, I do kind of wish there was a simple clear magnetic UV filter included as well, for the other 95% of the time l'm not using a filter for general photos. I also wish that the magnetic adapter ring had front threads so that a regular screw on filter could be used when not using the magnetic filters. I would also like that the different filters were colored differently, rather than all being orange, to make it easier to identify which is which more easily when looking in a camera bag or the filter case. I also don't like that the adapter ring is a bit larger than the 67mm threads; the ring is a bit larger in diameter than the lens diameter. It screws in properly, but it looks a little wonky, That's being nit picky though.

I don't see any obvious color cast with any of the filters but I didn't test them scientifically. If it is there, it is not obvious to my eyes. I also have not had the opportunity to test the variable ND on a wide-angle lens, so I can't comment on vignetting or if any cross pattern is generated with the variable ND. I will come back to edit this review once I have had a chance to test on a wide angle lens.

As far as value, these are well-designed, good quality filters, so the value is there. This can be a starter set for adding additional magnetic filters from their line.