Starink 4 Pack Replacement for HP 934XL 935XL HP 934 935 Patent High Yield Ink Cartridge Compatible with HP Officejet Pro 6230 6815 6812 6835 Inkjet Printer (1 Black, 1 Cyan, 1 Magenta, 1 Yellow) IMPORTANT: Please DO NOT upgrade your printers. The cartridges are not suitable for the upgraded system 1521AR & 1517AR. Pls pay more attention to it before buy them. Thanks for your patience. Compatible model,Non-OEM. 1 HP934XL Black, 1 HP935XL Black, 1 HP935XL Cyan, 1 HP935XL Magenta, 1 HP935XL Yellow. ( C2P23AN C2P24AN C2P25AN C2P26AN ) Compatible for: HP OfficeJet 6812 6815 Officejet Pro 6230 6835 e-All-in-One Color Inkjet Printer Starink Patent Chips. Large Ink Volume, High Yield, Big Savings. 24-month warranty and friendly customer service. All Starink products are manufactured according to ISO 9001 and ISO14001 and come with REACH, RoHS, CE and China Environmental Labelling.