Type Fountain pen with aerometric filing system.
Product Name New Duofold, "New" was added to the Duofold name when the aerometric system was adopted. This is just a little shorter than the button filled Senior.
Manufacturer and Year Parker, made in England -- 1950s or 60s (We couldn't find a date code on the barrel and there wasn't one on the nib, but the English Duofolds adopted aerometric systems in 1953).
Length 5-1/4". These are relatively fat pens, with barrel girth is .477 inches.
Filling System Aerometric squeeze filler like that of the later Parker 51s and the Parker 21s. We've cleaned and tested it and it's working very well.
Color Black cap and barrel with gold plated trim. Thin size cap band with a chevron pattern (it looks sort of like this: ////\\\\////\\\\). It has a matching black cap jewel. The pen is personalized with initials "M.I.B."
Nib EXTRA-FINE gold nib is marked D.
Condition Excellent condition with no cracks, chips, dents, or dings. This is a velvety black, shiny pen in a classic design. The barrel has light marks caused by the cap lip and from posting. There is a personalization, "M.I.D." The cap has moderate scratching to the left of the clip; it is otherwise quite nice. The decorated cap band has moderate microscratching and a tad of plating wear, but the pattern is intact. The arrow clip has microscratching, especially on the arrow end. The clip ring has some small, deep scratch or tool marks. The black top jewel has some miniscule dots. The imprint is clear.