coloretto remanufactured printer ink cartridge replacement for hp 901xl to use with hp officejet 4500 g510a g510g g510n j4500 j4524 j4624 j4660 j468 (1 black+1 color) combo pack coloretto outstanding reliability,easy to install and use,rival the original in clear and stable printing. installation guide: 1.take out cartridge and remove plastic protective cap if there's one. 2.tear off the protective tape by pulling the tab. 3.be careful not to touch the chip or the ink nozzle. 4.insert cartridge into the corresponding cabin,push firmly until it locks in place. notes: please confirm your printer model before placing order. any errors like "non-original cartridge","used","low ink" or "empty",please use a wipe (include in package) to wipe copper contact (chip),or reinstall them several times.