Speedy Inks Compatible Ink Cartridge Replacement for HP 934XL  ( Black , 2 pk ) For use in: OfficeJet 6812, OfficeJet 6815, OfficeJet Pro 6230, OfficeJet Pro 6830, & OfficeJet Pro 6835 Page Yield: 1,000* | *Average cartridge page yield in accordance with ISO IEC 24711 Shelf Life: 12-18 Months This professionally remanufactured cartridge for HP 934XL has a 'smart chip' that makes continuous adjustments to optimize print quality and enhance reliability and cost effectiveness as well as monitor ink levels The use of aftermarket replacement cartridges and supplies does not void your printer's warranty