I have a few Black Mist diffusers including the more expensive K&F Nano-X and the even more expensive Tiffen. I bought this version of the Nano K series halfway expecting to return it, but thought it was a test given the much lower cost. In terms of construction, it's just as solid and well-crafted as the Nano-X, using the same finely machined aircraft-grade aluminum. The screw thread is precise and smooth. K&F gives very little useful information about the actual differences between their filter series, except that the Nano-K is intended as a "base class" compared to the supposedly more professional Nano-X and Nano-X Pro series. If you read the manufacturer's fine print, they are all made of optical glass from Japan, are multi-coated and resistant to moisture and mold. So what about the effect power? Again, I was prepared for disappointment. All brands of this type of black diffusion filter have subtle differences, as numerous YouTube videos show. The Tiiffs, for example, tend to produce slightly less intense diffusion than the Nano-X at a given rating (i.e. 1/4 vs 1/8 etc.), but both are equally good at capturing the blacks and fine detail in preserving the mids, which is why we like them. Compared to the Nano-X, I can't see any visible difference in the image produced by the Nano-K. This was tested on a Canon C100 Mk-2 with a variety of lenses and conditions. For this reason, my advice would be when choosing between Nano-X and Nano-K without hesitation to choose the latter. A side note: the Nano K series appears to have been originally marketed in Germany, judging by Google searches and the fine print on the packaging i.e. GmbH as the place of origin. My conspiracy theory is that these were initially aimed at Europe's demographic and price expectations. Anyhow, the bottom line is they are a phenomenal bargain here in Canada/USA and shouldn't be missed while they're available. that these were initially aimed at Europe's demographic and price expectations. Anyhow, the bottom line is they are a phenomenal bargain here in Canada/USA and shouldn't be missed while they're available. that these were initially aimed at Europe's demographic and price expectations. Anyhow, the bottom line is they are a phenomenal bargain here in Canada/USA and shouldn't be missed while they're available.