Return Program toner cartridge is essential to Print System performance. Unison toner consistently delivers outstanding image quality, ensures long-life system reliability and promotes superior sustainability - all in an innovative, shake-free print system. Cartridge is compatible with MS321, MS421, MS521, MS621, MS622, MX321, MX421, MX521, MX522 and MX622. Genuine supplies are engineered to work best together with your printer, delivering excellent print quality from the first page to the last. Return Program cartridge is a patented device that is sold at a special price subject to the restriction that the cartridge may be used only once. Following the initial use, return the cartridge only to for remanufacture and/or recycling. Keep upfront costs low and quality high with Genuine cartridges. Perfect for low-volume printing, standard-yield cartridge yields approximately 6,000 pages.Return Program toner cartridge is essential to Print System performance. Unison toner consistently delivers outstanding image quality, ensures long-life system reliability and promotes superior sustainability - all in an innovative, shake-free print system. Cartridge is compatible with MS321, MS421, MS521, MS621, MS622, MX321, MX421, MX521, MX522 and MX622. Genuine supplies are engineered to work best together with your printer, delivering excellent print quality from the first page to the last. Return Program cartridge is a patented device that is sold at a special price subject to the restriction that the cartridge may be used only once. Following the initial use, return the cartridge only to for remanufacture and/or recycling. Keep upfront costs low and quality high with Genuine cartridges. Perfect for low-volume printing, standard-yield cartridge yields approximately 6,000 pages.