The quality I can not judge because I have returned this panel. Because the Tamron lens, has offered this panel EXPRESSLY for the Amazon ("Frequently Bought Together"), a separate panel brings !!!
From this panel is supplied with the lens the way, nothing to read ...
Incidentally, has the Tamron lens a "plant" their own very simple plug-in system for the in-house panel, whereas this diaphragm must be screwed into the filter ring, which sometimes stop is a fummlige matter and just when it should go quickly, not so simple is. Thus there was no reason for me to keep that part yet. So even said anything about the product itself.
I know that it is not entirely fair to devalue the aperture then, but Amazon's marketing I can not comment unfortunately, would be more appropriate at this point.