Pk/6 Kaweco Standard International Fountain Pen Ink Cartridges, Royal Blue Pack of 6 Kaweco standard international (also called universal) size ink cartridges. For all Kaweco fountain pens and any other fountain pen accepting the international format ink cartridge. Made in Germany. Additional Images: 1.5 long x .25 diameter The cartridges fit the following brands (compare your cartridge size to be sure as not all models take this universal cartridge):Acme, Ancora, Bossert & Erhard, Bexley, Caran d'Ache, Cartier, Colibri, Conklin, Conway Stewart, Daniel Hechter, DaniTrio, David Oscarson, Delta, Elysee, Faber Castell, Itoya, Jorg Hysek, J.P. Lepine, Lalax, Libelle, Loiminchay, Marlin, Michel Perchin, MontBlanc, Montegrappa, Monteverde, Nettuno, Northpoint, Omas, Pelikan, Recife, Regal, Retro 1951, Rosetta, Rotring, S T Dupont, Sensa, Signum, Stipula, Taccia, Tombow, Visconti, Waterford, Yard-O-Led & many others. These cartridges DO NOT FIT pens that take proprietary cartridges: Parker, Sheaffer, Cross, Waterman, Aurora, Lamy and Pilot.