Toner Refill Store's premium compatible Xerox black toner cartridges contain brand new parts and are 100% guaranteed to meet or exceed your expectations and surpass the print quality of the OEM (Original Equipment Manufacturer) Xerox 5021. Our Xerox 5021 monochrome toner cartridges are made from the highest quality materials and are manufactured in an ISO-9001 certified factory. Go green with our toner refill kits which allow you to refill your cartridge and reuse it! Toner Refill Store supplies each cartridge with a brand new smart chip which will get rid of your 'low toner' message. The use of our premium compatible laser toner cartridges for the Xerox 5021 does not void your printer's warranty. Our Xerox 5021 high yield laser toner cartridges have a 'One Year 100% Satisfaction Guarantee'.