Good product with potential for improvement

I have bought the item in a shop here in town and was first intimidated by the reviews here on Amazon a little, because the lens hood should be as difficult to handle.
Yet
..the metal ring can be easily screwed into the filter thread and also removed easily when this is not screwed too tightly. The actual bezel lets you push yourself by two lateral surfaces with which enter the four "hold claw", sit on the metal ring. The mounting and dismounting requires a little practice and is certainly not the best solution, but it's not as hard as it is described in some reviews in my view.
I had the aperture so about 10 times attaching and detaching and after that I had no more problems with it.

I express de two areas with the thumb and middle finger.
The index finger and the ring finger I use to make the aperture does not deform and is therefore easier to set up.

I can not say anything yet about durability at the present time.