The HP DeskJet 940cvr uses two ink cartridges. Compatible HP 15 (C6615DN) is the standard black ink, rated at about 840 pages. Compatible HP 78 (C6578AN) is the standard tri-color ink, rated at about 710 pages. The same supplies also fit the HP DeskJet 940C, DeskJet 920C and OfficeJet 5110. Same-day shipping on most orders.
