Return Program ink cartridges deliver outstanding results page after page in your Lexmark X3650, X4650, X5650, X5650ES, X6650, X6675 and Z2420. Superior Lexmark design means precision pairing between printer and cartridge for value, quality and environmental responsibility you can count on. Nonrefillable cartridges are licensed for single use only. 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 and return it only to Lexmark for re-manufacturing or recycling. Each cartridge yields approximately 150 pages.