Lexmark Return Program Cartridges are sold at a discount versus the prices of regular cartridges in exchange for the customer’s agreement to use the cartridge only once & return it only to Lexmark for remanufacturing or recycling. Regular cartridges without this license/agreement sold at regular prices are also available. Regular cartridges are also recyclable at no cost through Lexmark Cartridge Collection Program. Lexmark X644e & X646e MFP supplies are designed for the highest quality output, performance & easy installation, from the first page to the last. Lexmark X644e & X646e MFP supplies are not compatible with other Lexmark Printers. Average Cartridge Yield 21, 000 standard pages. Declared yield value in accordance with ISO/IEC 19752.- Lexmark X644e & X646e MFP supplies are designed for the highest quality output, performance & easy installation, from the first page to the last. Lexmark X644e & X646e MFP supplies are not compatible with other Lexmark Printers.- True: Accurate technology. Genuine quality. Environmental focus. Its our nature.- Image: Crisp print. Professional documents. Great Impressions. Project your character.- Always: Dependable. Page after page. Year after year. Count on Lexmark.