The No.20 was one of the very few Button Fillers produced by Conway Stewart in the years leading up to the war. They are now extremely rare, this is the only one I have seen.
The No.20 is a large pen, finished in Brown Marble with a gold filled clip and twin cap bands.
The Duro nib is huge and writes well with a Medium line and a gentle flex (unusual for a Duro nib).
It is not in perfect condition, there is some slight dicolouration of the marble towards the bottom of the barrel and the surface of the cap is lightly rippled in places. However it is a great working example of this rare pen and it is still a very desirable model. The imprint is clear and and legible and the button fillling mechanism is in excellent working condition.