Model 400N was introduced in December 1955. The suffix "N" (neu: "new") was added to the model name, but the changes were only in appearance. Günter Wagner regarded model 400N as "a model with improved shape".The main changes were:

• The cap tube and clip became longer and more streamlined. 

• The turning knob became more rounded and slightly longer.​

The model was only in production for one year, and was discontinued in 1956. As produced for a limited period of time, the model is now one of the rarest of vintage Pelikan pens.​