Having bought this exact stuff, I would say, that surprisingly, the weakest links are the holder/adaptor rings ... I bought several of each, but they are all suspect, difficult to put the holders on the rings. I would like to buy an example of the real thing and then try the filters themselves (1, 2 and 3 stop graduated and solid ND), because they seem fine.
https://photography-on-the.net …/showthread.php?t=1067943
The price is right, though ...
Maxdave
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