HP No 88 22.8ml Black Inkjet Cartridge. For Officejet Pro K550. OEM Ref - C9385AE. Hewlett Packard is dedicated to providing the very best printing for homes and offices, creating high quality machines and cartridges. Its products work together in perfect harmony, ensuring that you never have to worry about getting the results that you want. Producing a wide range of colours, from the very starkest, richest colours to more subtle hues, this cartridge is ideal for creating nuanced and detailed images.