Good
Bought a few filters for my lins to test out ND and polarisation from Nano-K serie, they are quite cheap compared to other exclusive brands and have nothing to complain about. Works as intended and will try out the Nano-X for my more expensive lenses. Only "downside" is the shipping from Asia is a bit slow so if you want it fast you can buy from Amazon, but to a higher price. They often have discounts on their website.