HP No 88 10ml Magenta Inkjet Cartridge. For Officejet PRO K550 Series Printers. OEM Ref - C9387AE. Formulated to deliver rich, colour intense images the HP Magenta No.88 Deskjet cartridge guarantees professional quality results from the first page to the last. With a large page and character yield, this original deskjet cartridge provides both value for money and the quality you expect from HP. HP are the world leaders in printing innovation, holding hundreds of patents in ink chemistry and rolling out over100 new inks in the last two decades.