Keep very clean

Unfortunately, this protective seals not round and has only a very small
Distance from the display surface. With me now have 2 times dust, respectively.
Sand grains successfully made their way between protection and display. Since that struck immediately and the protection constantly beautiful incorporate back and herwackelt could the grain of sand really deep at one point on the display! I now have a real deep scratches on the display it would not have certainly given without these "protection" as a grain of sand would simply dropped.
It is also now one of the eyelets canceled.

I think a self-adhesive film is better off (or seal)
To what extent can this disc absorb impact forces and transferred to the frame seems to me doubtful. For this purpose of this part is way too soft.

Otherwise, it fits well and does not interfere.

Addendum:
Even without the display film does not seem to scratch. Is probably similar coated as eyeglass plastic lenses that can scratch even with sandpaper.