Compatible with: Lexmark MS810de, MS810dn, MS810dtn, MS810n, MS811dn, MS811dtn, MS811n, MS812de, MS812dn, and MS812dtn Compatible Replacements Included: 3 pack 52D1000 black Lexmark 521 Toner Cartridges Standard Yield Delivers 6,000 pages just like the original Lexmark 521 compatible toner cartridge Average cartridge Page Yield* in accordance with ISO IEC 24711. *at 5% coverage (ISO/IEC standard) This is the standard yield version of Lexmark compatible toner cartridge 521