The 556/S and 556/F models, which Omas introduced in the late 1940s  soon became their most successful models  of the time. They are light and reliable writing instruments whose size is suitable for medium sized hands. 

The black celluloid is very stable and does not move and these pens are generally found in perfect aesthetic condition.

The nibs used on these models are of the highest quality: Omas Extra nibs for the cylindrical models and Omas Extra Lucens nibs for the facetted models. They offer a smooth writing experience and can be extremely springy and flexible.

This Omas Extra 556/F is in excellent condition and it is fitted with a very pleasant flexible nib, grade F