Printheads like this HP 771 unit regulate the flow of ink from your cartridge and are responsible for the print quality you have come to enjoy from your printer. Dealing exclusively with both photo black and light grey coloured ink, the CE020A has to work with a level of precision that you can only trust Hewlett Packard to deliver.Many, many prints can be produced with the CE020A before is needs changing and its replacement in compatible printers like the HP Designjet Z6200 42-in will certainly be a rarity. Thankfully Hewlett Packard have made installing the CE020A as simple and pain-free as possible.