Premium 56F1X00 Extra High Yield Black Toner Cartridge fully compatible with the Lexmark MS421dn, MS421dw, MS521dn, MS621dn, MS622de, MX321adw, MX421ade, MX521de, MX521ade, MX522adhe, MX622ade, MX622adhe. The use of compatible supplies does not void your printer warranty.