Piston filler including a 24 carat gold plating and an elaborately striped body made of celluloid acetate. The nib of the Souverän piston filler nibs of the models M600  are made of 14 carat/585 gold. All nibs are refined with a rhodium decor and their writing qualities were tested by hand. The fountain pens are equipped with a differential piston-filling mechanism,

Piston filler with a 24 carat gold plating and a high-quality resin casing and a viewing window to monitor the ink level.