These will fit many European and far eastern pen manufacturers' pens. On our site, this includes Waterman, Visconti and Online but NOT Parker, Lamy or Sheaffer.
Diamine Red Ink Cartridges Universal for most pens
Acroball ballpoint pen writes with the smoothness of a liquid ink rollerball while giving you the fast drying and long-lasting qualities of a ballpoint.Retractable Medium 1mm tip writes with a 0.32mm line width.