51626A Black Inkjet Cartridge compatible with the HP 2276a/ 2277a/ 2279a DeskWriter/ C2121A/ C2124A/ DesignJet 200/ 220/ 600/ DeskJet 200cci/ 400/ 420/ 500/ 505k/ 510/ 520/ 540/ 550c/ 560c/ DeskJet Plus/ DeskWriter 400 Also fits Agfa/ Apollo/ Apple/ Citizen/ Daewoo/ DEC/ Encad/ Olivetti/ Olympia/ Panasonic/ Pitney Bowes/ Sharp/ Siemens/ Stielow/ Triumph Adler/ and many other. The use of compatible supplies does not void your printer warranty.