Speedy Inks - Remanufactured Replacement for HP 91 / HP91 / C9468A Magenta Ink Cartridge For use in: DesignJet Z6100, DesignJet Z6100ps This professionally remanufactured cartridge for HP 91 has a 'smart chip' that makes continuous adjustments to optimize print quality and enhance reliability and cost effectiveness as well as monitor ink levels. Shelf Life: 12-18 Months Color: Magenta The use of aftermarket replacement cartridges and supplies does not void your printer's warranty