The 55X series of piston fillers was introduced by Omas at the end ot the 1940's.
It comprised cylindrical and facetted models in three sizes: 555, 556 and 557. Facetted models were identified with the letter F following the model number.
This line of pens was extremely successful and remained in production till the 1960's. All the models were highly reliable everyday users and had very beautiful 14 ct nibs.
The facetted line was fitted with Omas Extra Lucens nibs, exactly like the ones Omas had used in the 1930's for the top line of the Extra lucens pens, while cylindrical pens had Omas Extra nibs.
The first Omas 557/F pens to be marketed had a simple "Omas Extra" imprint on the barrel. In the following years, the imprint on the facetted models was updated witht he addition of patent numbers.
This Omas 556/F in gray pearl celluloid is in excellent condition with only a slight greenish shade of the celluloid. Gray pearl celluloid can in fact take on a greenish shade with time. The nib is EF, very smooth and pleasant to use.
The pen is priced on the basis of condition.