Toner cartridge is designed for use with Lexmark T640, T640dn, T640dtn, T640n, T642, T642dtn, T642n, T642tn, T644, T644dtn, T644n, T644dtn and T644tn for outstanding results page after page. Superior Lexmark design means precision pairing between printer and cartridge for value, quality and environmental responsibility you can count on. Lexmark Return Program Cartridges are sold at a discount, vs. the prices of regular cartridges, in exchange for the customer's agreement to use the cartridge only once and return it only to Lexmark for remanufacturing or recycling. Cartridge yields approximately 6,000 pages.