For me, K&F has been always a good balance between quality and value in photography - reliable and well-made enough to trust the brand while not breaking the bank over accessory purchases that often add up. And this filter set is no exception. A nice, well-functioning set of relevant filters that I can actually use, that's also made with quality.Pic.1: the packaging & what's includedPic.2: inner contents and the six filters in their carrying case.Pic.3, 4: next to my Osmo Nano (Pic.3) and with CPL filter that nicely fits when installed on Osmo Nano in the Protective Case (Pic.4)Pic.5 & 6: Compare - No filter (Pic.5) vs. With ND 64 installed (Pic.6)Pic.7 & 8: Compare - No filter (Pic.7) vs. With CPL installed (Pic.8)Pros.- Optical Quality: NDs seem consistent and without any unusual defects/artifacts across different strengths. CPL was also consistent and performed as expected (although a bit tricky to screw in or turn at first - yet again, blame it on Osmo's tiny filter design)- Well machined: fits Osmo Nano and its accompanying Protective Case perfectly, screws on/off easily enough (*not* necessarily extremely easy, but these are tiny screw-in filters and it's expected) All in all, each individual filter was visibly built well, without any mechanical/cosmetic blemishes or flaws that are found on cheaply filters.- Comes in a handy carrying case and wiping clothCons.- The carrying case looks a bit cheap, and *TOO BIG*. The whole idea about Osmo Nano is being small, and K&F could have made the carrying case - while still holding all 6 filters - a whole lot smaller and more portable to fit Osmo Nano's ethos. Possibly a missed opportunity, but at least the real products (filters) themselves are very good.Conclusion:A great tool for Osmo Nano Videography. Too bad my examples are simple photos for you to compare, but one definite use case for videography with these ND filters is - especially if you're riding a bicycle or motorbike - smoothing out the motion and decreasing the sharpening artifacts on roads. Because despite all I love about Osmo Nano's capability, (I'm also sorta using this as an onboard black box cam) the passing road clips would leave weird artifact and NDs were helpful.