The Pilot Parallel Pen in 3.8mm with a Green cap signifies a major breakthrough in calligraphy pen design! The pen features a nib that consists of a unique parallel plate structure which achieves more beautiful and sharper handwriting than existing calligraphy pens. Ink cartridges can be switched in the pen to create gradually changing color lines and mixed colors. Each set comes with a Parallel Pen, one black and one red ink cartridge, a blue bulb syringe for flushing and a nib cleaner.