Two are the visible changes:
3rd, on top, and 2nd generation, on bottom, of Petit-1 pens. Note the longer barrel of the newer pen.
First, and more visible, the barrel is now 5 mm longer. As a result, the cartridge can be stored inside without actually inking the pen. This makes the packaging of this pen easier for Pilot—the pens are now sold without any bag. The sealed cartridges carry a plastic piece to avoid inking the pen accidentally. The instructions, mostly how to remove this safety piece and how to ink the pen, are written on a sticker attached to the pen. However, these extra 5 mm in the barrel are not enough for the pen to use regular Pilot cartridges nor any of the Pilot converters.
All three generations of this pen: 3rd on top, 1st on bottom. Note the yellow plastic piece on the cartridge of the third generation. It prevents accidental inking of the pen.
The packaging of the three generations of Petit-1. Newer on top, old on bottom. The first generation was inked before delivered.
The second variation is on the number of colors and variations this pen is available. The second generation was found on five different body colors that did not necessarily match the eight inks available in the cartridges that are specific for this pen. This third generation is available in eight colors, shown on clip and barrel, matching the available inks.
The new eight colors of the 3rd generation Petit-1. They match the existing line of ink colors in the Pilot Petit line of pens.
The price –JPY 210— has not changed. It is the same as for the nominally disposable Vpen (Varsity in some markets) with which the Petit-1 shares the nib.
These are the dimensions:
............................2nd generation.................3rd generation
Diameter: .......................13 mm.................................13 mm
Length closed:............. 104 mm.............................. 109 mm
Length open:.................. 90 mm ................................95 mm
Length posted:............. 128 mm ..............................133 mm
Weight (inked):................. 9.9 g .................................10.4 g
It seems this longer barrel obeys mostly to the simplification of the packaging, but at the same time it makes this pen more comfortable to use.