The Montblanc No. 34 is a classical piston filler, no suction filler with pipette like the old Safety models. The rear rotary piston must be movable for a complete filling process over several rotations. If it can only be moved barely, mostly the piston mechanism is dried up, and the pen should first be soaked for a longer time before further turning. Caution is in order, because the spindle of the piston mechanism can consist of plastic and easily breaks off with force application.