The third rung of the Souverän ladder, introduced in 1985 and resized in 1997 to sit properly between the M400 and the M1000.
Where the specimen was made, by whom, and which generation it belongs to.
The metal between the writer and the page: its size, shape, material, and how willingly it bends.
How the pen takes ink, holds it, and releases it under the nib.
What the pen is made of, how it closes, and how light passes through it.
Every measurement in millimetres and grams, against the archive's range.
Designer, year released, the family the pen belongs to, and what came before it.
Warranty, repair channels, the boxed contents, and where the world stocks it.
How it sits in the hand, and the editor's reading of its temperament after a month at the desk.