The Duofold Aerometric is one of a succession of Duofolds Parker has produced since the name featured on a pen launched in 1922 in the U.S.A. Indeed, 65 years later, in 1987, Parker perpetuated the name with a Duofold Centennial Fountain Pen issued in anticipation of the 100th anniversary of the Parker company.  

The Aerometric was introduced in 1953, replacing its immediate predecessor the AF Duofold (AF = Aluminum Filler) which had been in production since 1948. The Duofold Aerometric continued in production until 1963. 

The Aerometric Duofold has a number of interesting features which were departures from the then norm of fountain pens. 

Perhaps the most important was the implementation by the English Parker Company of the "aerometric filler",  first featured on the famous Parker 51 range in 1948, the ink sac being compressed directly with a simple metal spring pressure bar, operated from the side by thumb and forefinger.  

At the same time Parker introduced the plastic ink sac which, unlike the more usual rubber sacs, does not harden and perish with age, and as time has told, the plastic sac has been very durable. 

Finally these pens feature an internal breather tube, which ensures rapid filling and a well regulated ink flow.

The pen came in a number of sizes: 

• the standard "Duofold" and "Demi Duofold" introduced in 1953
• the longer "Senior" (14.2cm) introduced in1954
• the comparatively huge "Maxima" (1958). 
• a ladies version, the "Lady Duofold" with a hooded nib (also in 1958). 
• Junior Duofold and a Slimfold (1962)

Colours available were solid black, blue, green and red. 

All have screw-on caps with the distinctive Parker narrow "arrow" clip with a single, narrow decorated rolled gold cap band with the zig-zag pattern and engraving blank (for very tiny initials!). The clip features a plastic "jewel" stud matching the pen colour.

These have continued to been popular reliable "work horse" pens since their introduction fifty years ago.  They are great writers and in good condition they make an excellent choice for every day use. 

Usually we have most models in stock in most colours.