The HP No. 21 and No. 22 printer ink combo pack has all the black and colour ink you’ll need to keep your DeskJet, OfficeJet or PSC printer pushing out high quality prints. There may only be two ink cartridges but all three colour inks are contained in the single tri-colour (Cyan, Magenta and Yellow) cartridge. This makes the HP No. 20 and No. 22 ink cartridges really easy to deal with when it comes time to swap out the empties. Order an extra set to make sure you always have ink in stock when you need it.