Hans Grohe Raindance Connect Showerpipe 27164001 Installation Instructions / Warranty page 5

If the bottom of the showerpipe is mounted on tile, but
the top is not, install the top wall flange with the tile
matching disk.
Push the shower arm and lower support into the ends of
the riser. Install the escutcheons.
Push the showerpipe assembly over the wall flanges.
Tighten the set screws with a  mm Allen wrench.
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