This offer includes (4) F6T80AN black ink cartridges; they replace the 972A standard yield ink series. This set is compatible with HP PageWide Pro 352dw, 377dw, 452dn, 477dn, 477dw, 552dw and 577z printers. Please note, retail packaging may vary and these ink cartridges will only work with printers purchased within the United States and Canada. The use of compatible printing supplies does not void your printer warranty. HP does not manufacture our compatible ink cartridges. We are the exclusive reseller of LD Products brand of high quality printing supplies.