Aperture fits perfectly, but ...

The panel fits really perfect in my Smart 451st
Disappointingly, only the "Installation instructions" mentioned in the package.
A unilateral, small piece feeding paper with a blurred black / white image and hardly text.
For example, it is only mentioned that that the metal frame with the enclosed brass parts can be adjusted continuously.
How to get the brass parts to the metal frame together sets is not mentioned.
The blurred image of help here also not, because as I have also composed - the hole recesses were never shown in the picture.
I then used the metal frame that came with my radio together.

Conclusion:
The panel is 5 stars. The metal frame with the stepless adjustment I can not evaluate.
The "Installation Guide" is a joke and gets 1 star.
Those who already have a metal frame, can actually buy only the iris from my perspective.
If I remember correctly, which is also sold separately and therefore cheaper.