The metal ring, which is screwed into the filter thread is solid and the thread is leichtgänig. The additional internal thread can further filter and (or) use the lens cap.
The panel must be removed with a handle of the metal ring and also placed almost as quickly with a little practice.
The appearance of the part is a matter of taste. Worse than the plastic parts, which you can get for a lot more money else, but it's not. Much more convincing me the ease of use by the rapid on and remove these rubber diaphragm, whereby the metal ring with the recording, can verbleinen on the lens.
In this "inner tube material," I expect a similar durability. So ca.7Jahre until the softener is out and the material becomes brittle. But nothing lasts forever.
In my lens on the Olympus PEN 17mm with 35mm filter thread, there were limited size at the corners black spots. For the iris, however, can not, because that is where something small filter thread, whereby the aperture relative has a rather small diameter. I simply just using a carpet knife, to the cast grooves along, cut off a piece. Cutting is easier than cut off. The visor is still long enough and now served its purpose 100%.
The price - performance - Verhältinis is of course a relative term. Compared with the prices of brand-name manufacturers, it is absolutely unbeatable! In addition, for how much (or little) money these things were probably made once, of course, one must not make any big thoughts.
