Speedy Inks Compatible Toner Cartridge Replacements for Lexmark 521 52D1000 (Black, 6-Pack) For use in: Lexmark MS810de, Lexmark MS810dn, Lexmark MS810dtn, Lexmark MS810n, Lexmark MS811n, Lexmark MS811dn, Lexmark MS812dn, Lexmark MS812dtn, Lexmark MS812de, Lexmark MS811dtn Page Yield: 6000 Shelf Life: 24-36 Months Color: Black The use of aftermarket replacement cartridges and supplies does not void your printer's warranty