Miele DA 3668 Operating And Installation Instructions page 58

Installation
 The covers for the brackets are
designed for 16 mm and 19 mm thick
unit sides. Turn the covers so that
they are in the appropriate position
and fit them onto the brackets.
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 Secure the spacer strip to the bottom
of the wall unit as well.
 Insert the cover for the charcoal filter
slots as shown and close it. It is held
in place by magnets.