This pen is now sold but a Parker 21 Super in Green is available here

The Parker 21 Mk.1 was only made from 1948 to 1951 when the section and cap design were modified for the Mk. 2 version, a more practical pen than the original.  In 1953 the Parker 21 Super, this pen, was introduced. 

This is a particularly fine example. Finished in Black, with a stainless steel cap and a redesigned 'arrow' clip, it is in fabulous, near mint condition.

The pen appears to have seen little use, it is unmarked and has an unstained 'Pli-glass' ink sac.  Even so the pen was disassembled, checked, thoroughly cleaned and tested.  I have included a photograph before reassembly, it isn't often that a 21 nib is seen in all its glory!

The filling system, a modified 'Aerometric', works well and the parker 'Octanium' nib writes with a very smooth and consistent fine line, a very 'easy' writer.  It would suit a person with small handwriting and also for detailed work.

The Parker 21 is an extremely good choice as an unusual and dependable every day writer and is often favoured rather than the much more expensive Parker 51 to which it bears a close, if superficial resemblance.  It is an excellent pen in its own right.