Hans Grohe AXOR Citterio M 34444 1 Series Installation Instructions / Warranty page 4

Install the new cartridges.
The cold cartridge is marked with notches on the wrench
flats.
Hold the valve steady with a 5 mm wrench while tighten-
ing the cartridge with a 17 mm wrench.
Take care not to overtighten or damage to the valve may
result!
Place the square escutcheon over the valve.
Place the nut over the valve and escutcheon. Tighten the
nut with the special tool.
Install the round flange.
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