Miele DA 4208V D Operating And Installation Instructions page 44

Installation
 Use a knife to release the four
spacers and the two covers from the
spacer frame supplied.
 Use the spacer frame as a drilling
template. Place it on the ceiling with
the arrows pointing forwards. Using
the notches, align the spacer frame
on the intersecting lines and make
pencil marks for the drill holes.
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 Drill four holes  10 mm, approx.
115 mm deep for the plugs supplied.
 Place the four plugs in the holes and
screw in the 4 screws so that they
protrude by approx. 30 mm.