GREENSKY 8 Packs(2B 2C 2Y 2M) High Capacity Value Pack Replacement for HP 934XL 935XL Fit Used in HP OfficeJet Pro 6830 6820 6230 6812 6815 6835 Printer Package: HP934XL 935XL Ink cartridges 8PK ( 2Black 2Cyan 2Yellow 2Magenta) Page Yield: up to 1000 Pages for Black & 550 Pages for Color at 5% coverage Compatible with HP OfficeJet Pro 6830 6820 6230 6812 6815 6835 Printer 3-Years 100% Quality Guarantee ensures that you will get quality printouts with our compatible or remanufactured cartridges. Any problems under normal circumstance, Request for return is acceptable Pls accept our sincere apologize. As we got news that the printers was updated recently, however, our new inks has been installed with new chip, but some of our old inventory may the printer can not recognize the ink or showing other error massage. If you have any problem when you install the ink, please kindly contact GREENSKY after service, we will resolve it ASAP.