Black No. 36XL Return Program Print Cartridge for Lexmark X3650,X4650,X5650,X6675,X6675,Z2420 Printers. The No 36XL black cartridge reflects a discount (Discount reflects the difference between Lexmark's suggested street prices for the equivalent cartridges; actual cartridge prices and effective discount may vary based on reseller pricing and promotions) compared to alternative cartridges in exchange for agreeing to return the used cartridges only to Lexmark for remanufacturing or recycling.