The variety of models Waterman offered in the 1920s was meant to cover any possible writing need and to meet as many as possible taste requirements. Buyers could choose from a large array of silver, gold filled and solid overlays and a variety of nib grades with more or less flexibility. Sizes could be modulated on the basis of the size of users' hands, with standard sizes suitable for male, large hands, slender 1/2 sizes suitable for the feminine  market and  V, shorter size, for junior writers which could also have 1/2 V models, short and slender.

This Waterman 452 1/2 PSF is an example of a very appealing gold filled filigree overlay on black ebonite on a slender model which looks more suitable for a feminine writer than a male hand. 

The nib is EF, flexible and smooth.

The pen is in excellent condition with no signs of brassing  nor dings. It has been recently resacked and it is ready to write.

The acronym PSF means: pocket self filler