The HP OfficeJet R40 uses two compatible ink cartridges: the HP 45 (51645A) in black, rated at about 1,100 pages, and the HP 23 (C1823D) in tri-color, rated at about 690 pages. Both are standard capacity. The same supplies also fit the OfficeJet R45, OfficeJet R60 and OfficeJet R80. Same-day shipping on most orders.
