56F1000 Black. OEM Number: 56F1000,56F000G. Lexmark MS321dn, Lexmark MS421dn, Lexmark MS421dw, Lexmark MS521dn, Lexmark MS621dn, Lexmark MS622de, Lexmark MX321adn, Lexmark MX321adw, Lexmark MX421ade, Lexmark MX521ade, Lexmark MX521de, Lexmark MX522adhe, Lexmark MX622ade, Lexmark MX622adhe.
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