Private Reserve Fountain Pen Ink Cartridges, Ebony Purple12 mini cartridgesStandard international size1.5" long x .25" diameterExcellent coverageSmooth flowVibrant colorNeutral pHNon-cloggingFast dryingThe 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, Sheaffer, 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.Available in 45 colors in bottles and 44 colors in cartridges - check our store for the full selection